Friday, October 6, 2017

NASA: On to the Moon!

The moon shines bright, in such a night as this.

- William Shakespeare.

VP Pence National Space Council
Vice President Mike Pence speaking at the National Space Council , October 5, 2017 (photos courtesy of NASA unless otherwise indicated).

About every five minutes, NASA changes its focus. It's asteroids, then it's Mars, deep space probes, and they even throw Venus into the mix occasionally with fanciful Youtube videos.

In October 2017, another change of focus, and one that actually makes sense given the capabilities of the US space program.

A mission to the Moon.

President Trump
President Donald Trump, here with astronaut Kate Rubins and Ivanka Trump on 24 April 2017, has put VP Pence in charge of NASA policy (Photo: Susan Walsh/AP).

It is perhaps a bit silly to spend too much time on any of NASA's ever-shifting priorities, but the Moon has one prime attraction: NASA knows that it can actually get there and complete missions on the Lunar surface. The only things NASA has sent to Mars are rovers which send back nice pictures but don't really settle conclusively issues such as ancient life. While their scientific missions are extremely interesting and educational, the rovers are limited for any number of reasons. As for sending manned missions to Mars... regardless of what else you may hear, those are still in the realm of science fiction and will remain so for decades.

Gerstenmaier Space Shuttle Endeavour
William Gerstenmaier, right, examines scorched tiles on space shuttle Endeavour in 2007.

NASA itself knows that Mars is beyond its capabilities. Oh, NASA could do it - if you gave it unlimited amounts of money and time. It also could go to Alpha Centauri, too, given the same latitude. However, we live in the real world, something acknowledged by NASA's chief of human spaceflight William H. Gerstenmaier in July 2017:
I can't put a date on humans on Mars, and the reason really is the other piece is, at the budget levels we described, this roughly 2 percent increase, we don’t have the surface systems available for Mars. And that entry, descent and landing is a huge challenge for us for Mars.
Anyone closely following the progress of the US space program knew this already, but it was nice to actually hear the truth from NASA itself.

Astronaut Moon
As of 2017, no human has been out of low-earth orbit, let alone to the Moon, since the Nixon administration in the early 1970s.

Okay, so now you think I'm nothing but a Negative Nancy or something. Why, of course we can just fly off to Mars on schedule, you say. Well, NASA says that we can't. Instead, on 5 October 2017, Vice President Mike Pence signalled the new focus of the space program at a space council meeting:
We will return American astronauts to the Moon, not only to leave behind footprints and flags, but to build the foundation we need to send Americans to Mars and beyond. The Moon will be a stepping-stone, a training ground, a venue to strengthen our commercial and international partnerships as we refocus America’s space program toward human space exploration.
So, there's the new priority. Presumably, President Trump's pick to head NASA, Representative Jim Bridenstine (R–OK), is on board with this plan.

Jessica Duckworth Robert Aderholt
Jessica Duckworth, left, U.S. Rep. Robert Aderholt of Alabama, center, and VP Pence.

In a battle cry that resonates, Pence said:
America seems to have lost our edge in space,” said Pence, “and those days are over.
There is a lot of skepticism about this focus on the Moon, figuring it is unfeasible. Interestingly, much of it comes from those who though going to Mars was doable. Since going to Mars would be vastly more complicated and risky than going to the Moon again, a trip to the Moon should be fairly straightforward if it is done instead of going to Mars.

NASA Marshall Space Flight Center
NASA's Marshall Space Flight Center in Huntsville, Alabama.

Pence gave an idea how this would be achieved:
American companies are on the cutting edge of space technology, and they’re developing new rockets, spaceships, and satellites that will take us further into space faster than ever before. By fostering much stronger partnerships between the federal government and the realm of industry, and bringing the full force of our national interests to bear, American leadership in space will be assured.
VP Pence has been working on this new policy assiduously. He visited NASA's Marshall Space Flight Center in Huntsville, Alabama, on Monday, Sept. 25, 2017. This gave Pence some first-hand looks at what actually is achievable, rather than simply drinking in the wishes and hopes of people obsessed with Mars.

Astronaut Moon Apollo 11
The U.S. flag still stands on the surface of the Moon, and may be joined by another one in the not-too-distant future.

In any event, it is all just talk for now. It would be nice to see NASA actually do some things they plan, rather than just talk about them. We shall continue following events hopefully.


Saturday, May 13, 2017

NASA's Roadmap To Mars

NASA Deep Space Gateway
An artist's conception of the Deep Space Gateway, intended to gain experience in cislunar orbit, operating near an Orion crew vehicle (NASA illustration).

The National Aeronautics and Space Administration (NASA) releases updated plans for a Mars Mission seemingly every month. The agency seems obsessed with the Red Planet, though so far it has focused its manned space activities entirely on low-Earth orbit missions (at least since 19 December 1972). Well, NASA is at it again: it held a "Humans to Mars 2017" conference at George Washington University on 11 May 2017 to discuss such a mission. While it was a lengthy conference providing lots of good information, let's focus on the parts that provide a specific roadmap for a mission to Mars.

Before you even think about going to Mars, you need the political will to do so. That appears to be present at the moment. Bill S.442, named the National Aeronautics and Space Administration Transition Authorization Act of 2017, was co-sponsored by Sen. Ted Cruz (R-TX) and Sen. Marco Rubio (R-FL). It provides NASA with $19.5 billion worth of funding for the fiscal 2018 year (beginning in September 2017). The objective of this funding is to create the foundation for a manned mission to Mars in the 2030s and to:
extend human presence [in space], including potential human habitation on another celestial body and a thriving space economy in the 21st Century.
President Trump signed the bill on 21 March 2017. All of this appears to point toward preparations for a Mars mission.

NASA Gregory J. Williams
NASA's Gregory J. Williams (NASA).

Gregory J. Williams outlined the current thinking on Mars mission. He is the Deputy Associate Administrator for Policy and Plans in NASA's Human Exploration and Operations Mission Directorate. Now, a general rule of thumb in life it that, the longer the title, the less real authority someone has. However, Williams at least gave a concrete outline for the progression from low-Earth orbit to setting foot on Mars. The ideas for this proposed mission are so preliminary that it doesn't even have a name yet.

NASA pathway to Mars
Phases on the road to Mars (NASA).

In a talk entitled "Defining NASA's Deep-Space Gateway and Transport Plan," Williams set forth four phases to get to Mars, with a preliminary phase currently in progress:

  • Phase 0: Using the International Space Station
  • Phase 1: Operating in the Lunar Vicinity
  • Phase 2: Complete Deep Space Transport System
  • Phases 3 and 4: Mission to Mars

Right away, you can see that the actual "getting to Mars" part is murky and vague. However, NASA seems to be firming up ideas on Phases 0-2, with Phases 3-4 too far away to pin down yet.

NASA astronaut Scott Kelly
Scott Kelly has a twin brother, Mark, who provides a baseline of physical data to show how extended stays in low-Earth orbit affect the body (NASA).

First things first. There are problems with any extended space travel that have to be addressed. It is well known that extended trips beyond low-Earth orbit are harmful to the human body (extended trips within low-Earth orbit also are harmful, but not nearly as much). For instance, astronaut Scott Kelly spent 340 consecutive days in space as part of his total 520 days in low-Earth orbit (he since has retired).  Upon examining him, NASA doctors found eight key physical effects just from being in zero gravity:

  1. Body liquids spread out more evenly
  2. You lose bone density without vigorous exercise
  3. Fluid shifts from your legs to your head (2 liters)
  4. Your vision deteriorates due to pressure changes in the brain
  5. Muscles shrink extra tissue is absorbed
  6. Sleeping is difficult and astronauts average only 6 hours a night
  7. Your risk of getting cancer increases due to cosmic rays
  8. Your spine stretches and you grow 3% taller

And that is while still within the earth's protective magnetic field. Furthermore, there even are changes in your genetic blueprint and the immune system (diminished capacity to respond to health issues).

All right, so there are issues that remain to be resolved. A trip to Mars and back would take an estimated thousand days, and the overwhelming majority of that time would be outside a planetary magnetic field, in weightlessness, and exposed to cosmic rays that might give you cancer. The ravages to the human body would be extreme. Still, there undoubtedly are uncounted volunteers who would be willing to pay any price to be among the first humans to set foot on Mars. Besides, NASA will "take care of it" and "figure out a solution." You know how it is, and I hope they can. So, let's put the physiological problems aside and look at the mechanical progression.

ESA astronaut Andre Kuipers
"European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, prepares vials in the Columbus laboratory of the International Space Station for venous blood sample draws during an immune system investigation" (NASA).

Phase 0, currently in progress, involves things like studying Kelly and the other astronauts to make progress on the physical issues of space travel. There will be research and systems testing on the International Space Station (ISS). This, of course, will continue in later stages, but at least some beginnings can be made on the process right now. Williams said that part of this phase is to “understand if and when lunar resources are available,” which hints at some kind of lunar landing at some point. If so, that undoubtedly would prolong the entire Mars mission.

The SLS, according to an unofficial NASA briefing of 9 May 2017, may be ready for launch (EM-1) as soon as September 2017. The Agency's "commitment" date is a launch by November 2017. This would be the first flight of SLS and the second for Orion and will be unmanned (NASA).

Phase 1 would entail operations in cislunar space (between the Earth and the Moon). This Phase would take place in the 2020s and include using the Space Launch System (SLS) to place equipment in orbit, assemble it, and then conduct at least five missions (manned and unmanned) in cislunar space. The parts of the Deep Space Transport itself would be among the items placed in orbit, as well as a habitat for crew members. This Phase would culminate in an extended mission - currently projected at a year and known informally as the "shakedown cruise" - by astronauts in cislunar space to try out the equipment. This shakedown cruise is tentatively scheduled for 2027. According to Williams:
If we could conduct a year-long crewed mission on this Deep Space Transport in cislunar space, we believe we will know enough that we could then send this thing, crewed, on a 1,000-day mission to the Mars system and back.
This cislunar phase is the most critical of the entire project, because it will get the equipment into orbit and test the ability of humans to use it. Of course, a lot could go wrong during this phase - what if you go to enormous effort to get equipment into space and then, when testing it out, it doesn't meet your needs? Or, what if the astronauts develop radiation symptoms? This is the phase that could stretch out the entire program.

NASA Mars Mission Phase 1 Plan
Steps in Phase 1 (NASA).

Phase 2 would see the completion of the Deep Space Transport. Now, the Deep Space Transport not only has not been built, it apparently has not even been designed yet. The concept envisions a reusable vehicle that uses electric and chemical propulsion for a voyage to Mars and other destinations. In any event, once completed in orbit, the Deep Space Transport would be sent, unmanned apparently, to orbit Mars. Williams says that details are "evolving," and this is the part where they are "evolving" the most. Assuming that Phase 1 goes according to plan and without disclosing any major problems, however, Phase 2 should be the easiest of the stages.

NASA Mars Mission Phase 2 and Phase 3
Steps in Phases 2 and 3 (NASA).

Phases 3 and 4 are simply outlines at the moment. Presumably, Phase 3 would involve manned orbits of Mars by the Deep Space Transport, much as Apollo 8 orbited the Moon during Christmas 1968 (and, to some, proved the highlight of the entire Apollo program, even exceeding the drama of the Apollo 11 Moon landing itself). There would be high drama in this mission, because it would be the true acid test on whether humans can make the trip and get back in some kind of healthy state. If Phase 1 is the most critical of the stages, Phase 3 would be the most dramatic in terms of the possible success or failure of a Mars landing during our lifetimes. If people can get to Mars orbit in one piece, getting down to the surface becomes a technical issue that engineers can work out using known technology (and perhaps borrow ideas from the Apollo program).

NASA Cis-Lunar station

Phase 4 would be the Mars landing itself. If the other Phases have been completed successfully, this should be the easiest Phase of all - though of course it will capture the most media attention. Williams was careful to point out that NASA is not doing all of this alone:
We're trying to lead this journey to Mars with a broad range of partnerships. One of the things we'll be doing over the next few years is putting that package together.
NASA's partners are expected to be SpaceX and Blue Origin. There has not been any hint of Russian, Chinese, or any other nation's involvement - this currently is "shaking down" as a purely American enterprise.


Thursday, March 30, 2017

Space Launch System (SLS)

SLS, The Next Giant Leap

SLS Space Launch System
Exciting developments at NASA! All images courtesy of NASA.
After years of stagnation, the US Space Program is showing some signs of life again.

SLS Space Launch System
The bottom stage alone dwarfs a human. All images courtesy of NASA.
The Space Launch System (SLS) now is undergoing testing at NASA’s Marshall Space Flight Center in Huntsville, Alabama.

SLS Space Launch System
Testing involves placing stresses on the components. All images courtesy of NASA.
The SLS will pair with the Orion spacecraft to give NASA the ability to get men and women outside of low earth orbit again after an interregnum of almost 50 years.

SLS Space Launch System
Adapters are the key to the SLS. All images courtesy of NASA.
Testing at Marshall is at a serious stage. Engineers have stacked four qualification articles of the upper part of SLS into a 65-foot-tall test stand using more than 3,000 bolts to hold the hardware together. Stress is being applied to make sure the apparatus will withstand the impact of liftoff, space flight, and a return to earth.

SLS Space Launch System
The four different stages are massive. All images courtesy of NASA.
The integrated tests are on four different components that are all connected:
  1. Launch Vehicle Adapter
  2. Frangible Joint Assembly
  3. Interim Cryogenic Propulsion Stage
  4. Orion Stage Adapter
Seriously, they should consider getting a better name for the Frangible Joint Assembly. I know, the engineers don't know from catchy names. Still, if you are going to spend so much money on fancy videos, why not spend five minutes of brainpower on assigning key components with something more interesting than "Frangible Joint Assembly.

SLS Space Launch System
Testing is underway on the different SLS parts. All images courtesy of NASA.
To provide a safety margin, the tests apply stresses of 40% greater than those expected in actual space flight. The stresses are applied by dozens of load pistons.

SLS Space Launch System
The craft breaks apart during the mission. All images courtesy of NASA.
It is a complicated spacecraft. Just like with ordinary plumbing that connects different sizes of pipes, the setup requires adapters to fit together the different parts of the craft. The Launch Vehicle Stage Adapter, LVSA, connects the SLS core stage and the Interim Cryogenic Propulsion Stage, ICPS. The LVSA test hardware is 26.5 feet tall, with a bottom diameter of 27.5 feet and a top diameter of 16.8 feet. The frangible joint, located between the LVSA and ICPS, is used to separate the two pieces of hardware during flight, allowing the ICPS to provide the thrust to send Orion onto its mission.

The SLS roughly is the size of the Saturn V. All images courtesy of NASA.
Another adapter is the Orion Stage Adapter. This connects the Orion spacecraft to the ICPS. It is 4.8 feet tall, with a 16.8-foot bottom diameter and 18-foot top diameter.

SLS Space Launch System
The SLS looks a bit like the Space Shuttle booster. All images courtesy of NASA.
The Interim Cryogenic Propulsion Stage (ICPS) is a liquid oxygen/liquid hydrogen-based system that will push Orion beyond the moon before it returns to Earth on the projected first flight of SLS in 2018. This test series aims to simulate that flight. The fuel tanks are filled with non-flammable liquid nitrogen and pressurized with gaseous nitrogen to simulate flight conditions. The nitrogen is chilled to the same temperature as the oxygen and hydrogen under launch conditions.

SLS Space Launch System
The objective is to finally get beyond low Earth orbit again. All images courtesy of NASA.
The first integrated flight for SLS and Orion in 2018 will allow NASA to use the lunar vicinity as a proving ground to test systems farther from Earth. The ultimate goal is to demonstrate that Orion can get to a stable orbit in the area of space near the moon. This is a necessary prerequisite to send humans deeper into space. Once this is accomplished, a voyage to Mars becomes a real possibility, perhaps by the 2030s.

SLS Space Launch System
The SLS is nearing completion for actual use. All images courtesy of NASA.
We wish NASA the best in this project. The future of the US Space Program in the 21st Century depends upon it.

Orion already is at an advanced stage of testing, but Orion is useless without the SLS to take it where it needs to go.