
Journey to Mars: Pioneering Next Steps in Space Exploration [pdf] - pp19dd
http://www.nasa.gov/sites/default/files/atoms/files/journey-to-mars-next-steps-20151008_508.pdf
======
hackuser
If you have any interest, I highly recommend reading this. It's not marketing
fluff; it has a creative and (seemingly) complete vision and well-thought-
through planning, and is clear, concise, and detailed. Maybe someone who
follows these issues closely will already know much of it (or maybe not; I
have no idea), but it is an education for me and by far the best thing I've
read on the subject.

For example, the three phases in the title are defined not by physical
locations or technological developments, but by dependence on Earth:

* Earth Reliant

* Proving Ground: R&D in 'cislunar' space

* Earth Independent

Maybe that's old news to space geeks, but it's new to me and shows an effort
to carefully conceive of the mission.

~~~
nickff
I wish that NASA's plan were wise and thoughtful... but it isn't.

NASA has created a plan which supports the continuation of all projects
currently running and in development as part of the 'path to Mars'. While this
may be a good jobs or aerospace stimulus spending program, these projects are
not critical to getting to Mars. If NASA were serious about going to Mars as
soon as possible, they would cancel the Space Launch System (SLS), and spend
the money on in-orbit low-gravity research, ion thruster research, and
SpaceX/Blue Origin/Orbital Sciences/ULA super-heavy lift capabilities. If they
did this, NASA could send astronauts to Mars in 2024. As things stand, SLS is
too expensive and slow a program to survive changes of administrations (i.e.
presidential elections), like its predecessors, SLS and its descendants will
go into cost/scope death spirals and get cancelled/restarted.

In short, if NASA really wanted to go to Mars, they'd focus on going to Mars.
If you're interested in the subject, I suggest you watch "The Mars
Underground", as it is a good primer on the recent history of Mars exploration
ideas/initiatives.[1]

[1] [http://documentarystorm.com/the-mars-
underground/](http://documentarystorm.com/the-mars-underground/)

~~~
jules
Why should we want to go to Mars at this point in time? Given the choice of
putting billions into going to Mars or doing something else, why should we go
to Mars? It seems to me that there are far better places to put this money.

~~~
nickff
This entire thread is based on the premise that sending humans to Mars is
desirable, and we are discussing how best to get there. The purpose of my
comment was to address how NASA should spend its money, not whether it should
have the money in the first place.

If you would like to discuss de-funding human spaceflight and/or NASA, I think
there are points for and against both, and would be interested to read your
thoughts on the matter.

~~~
jules
I understand, it's just that your comment made me doubt whether going to Mars
is a good idea at all :)

Why I thought that going to Mars might not be a great idea (yet):

NASA's budget is about 17 billion so lets guesstimate that going to Mars will
cost 100 billion. It's probably a lot more to establish a colony, let alone a
self sufficient colony. What is the benefit of having a colony on Mars? We
aren't lacking space on Earth; it would be a lot easier to colonize the
Saharan desert than to colonize Mars. Instead that money could go to
scientific research (e.g. renewable energy generation, medical research, AI
research, robotics research), or to some other cause. Wouldn't that be of much
greater benefit to humanity?

If you're looking purely at space exploration it also seems to me that there
are better ways to spend that money than to put humans on Mars. For the same
money we could probably put a whole bunch of telescopes in space and send
several probes/rovers to asteroids/planets/moons.

Even if the ultimate goal is to establish a colony on Mars, it might be a
better strategy to build it with robots than with humans...?

~~~
kvz
I recommend reading the last waitbutwhy post. Also available in audio, which
is nice to digest the material if you're doing a few hours of less
inspirational work

------
ohitsdom
I'm curious how much cost is added to the flight to Mars if they build a
tether/rotating system on the spacecraft to simulate gravity. Seems like too
much of a health risk to forgo this and spend years in micro-gravity, although
research is limited on the topic (the first two men in a year long study are
at ~7 months in space).

~~~
nickff
NASA has unfortunately been neglecting low-gravity (centripetal acceleration)
research. The only research I am aware of in this area was conducted by the
Soviet Union on mice, and (to the best of my recolection) they found that
~0.3G and relatively low RPM were required to maintain fitness. I agree with
you that further work is required on this subject, as it could help future
Martians to be healthier and more productive throughout their journey, but it
does not seem to jive with NASA's current priorities. NASA has repeatedly
rejected proposals for studies and experiments in this area.

~~~
baobabaobab
NASA actually did a tethered artificial gravity experiment during Gemini with
the target docking vehicle. They got it working, although they only spun it up
to like .01g.

~~~
nickff
From what I read, they were never even sure of what the centripetal
acceleration (G-force) actually was, because of the uncertainty of the
measurements. Either way, I suppose you could call this research, but I have
always categorized this as a proof of concept of a potential research method.

It should also be noted that NASA has had trouble with tethers in the past,
due to vibrations along the wire(s) and orbital mechanics related issues.

------
Animats
Congress failed to fund the Commercial Crew Program, which would have put
astronauts in space on Space-X boosters using the existing Falcon rocket and
Dragon capsule. Instead, NASA's pork programs are getting funding.

Colonizing Mars is a fantasy. The worst real estate on Earth can support life
better than the best real estate on Mars. It would be easier to colonize
Antarctica or underwater on a continental shelf than Mars. Send robots to look
around, sure. We now know what Mars looks like. Nearly airless, dusty, rocky,
maybe some brine or ice. Years of orbiters haven't found anything really
exciting that justifies more surface exploration.

The US should build a Venus lander that can survive that environment and let
us get a good look at Venus. The only surface pictures of Venus are from
Soviet spacecraft of the 1970s. It's time for another look.

~~~
pdabbadabba
> Years of orbiters haven't found anything really exciting that justifies more
> surface exploration.

Beyond liquid water, I'm not sure what more you could hope for. Little green
men, I guess?

------
richmarr
This is great & inspiring and all.

I just can't help pausing at the apparent tension between "we embark on this
journey for all humanity" and "strengthening America’s leadership on Earth and
in space".

There's certainly nothing wrong with the USA's space agency serving the
interests of the USA, and there will (eventually) be technology & economic
benefits for other nations too, I just find the language jars.

~~~
MrZongle2
The cynic in me says for you not to worry.

In 10 years the United States will (unfortunately) be no closer to landing a
man on Mars. The mess that is the Congressional budget process will guarantee
it.

Much like fusion and AI, an American on Mars always seems about 20-25 years
away.

------
shostack
Is it just me or has NASA really been on point with capitalizing on the PR
opportunity surrounding The Martian?

\- Numerous Reddit frontpage posts/AMA's

\- Great buzz around discoveries

\- This plan

Not knocking them--NASA needs all the love they can get. I've just become very
aware of a much larger NASA presence in my news sources than I'm used to.

~~~
pp19dd
Nah. For me it was this 70 MB photo of Pluto that convinced me that they're
not hyping anything, but delivering actual results:
[http://www.nasa.gov/sites/default/files/thumbnails/image/cro...](http://www.nasa.gov/sites/default/files/thumbnails/image/crop_p_color2_enhanced_release.png)

Think I spent half a day staring at that photo, just zooming and panning and
wishing I had a bigger screen. Anyhow, they bring up this data bandwidth issue
front and center in the PDF.

More to my point (if I had one), the probe was launched in 2006 and took 9
years to get there. The 70 MB photo was taken half a year ago and just now
managed to get transmitted (surely they had other things queued up and so
forth.) I don't think that I've done anything for 9 years, and I would never
wait half a year for a page to load, so NASA's convinced me that they can do
longevity.

------
devy
Not impressed. Considering Dr. Robert Zubrin's Mars Direct plan and later
revised Mars Semi-Direct plan announced in the early 90s even with the space
technologies back then. [1][2][3][4]

[1]:
[https://www.nasa.gov/pdf/376589main_04%20-%20Mars%20Direct%2...](https://www.nasa.gov/pdf/376589main_04%20-%20Mars%20Direct%20Power%20Point-7-30-09.pdf)

[2]:
[https://www.youtube.com/watch?v=L7ZDf5KZGAk](https://www.youtube.com/watch?v=L7ZDf5KZGAk)

[3]:
[https://www.youtube.com/watch?v=tcTZvNLL0-w](https://www.youtube.com/watch?v=tcTZvNLL0-w)

------
hackuser
Is there a web version of this? It's too bad if all this great information is
hidden away in a PDF, which few will bother to open (even on HN, and fewer in
the general public) and which I'll probably be unable to find in the future. I
found the following website, but my initial impression is that it's lacks a
lot of the great material in the PDF:

[http://www.nasa.gov/topics/journeytomars/index.html](http://www.nasa.gov/topics/journeytomars/index.html)

~~~
mpweiher
Why? I click on the link and it opens in the browser like any other content.
Except that it's easier to download.

~~~
hackuser
> I click on the link and it opens in the browser like any other content

That's one thing I'm not doing. IME Firefox's PDF rendering is worse than
external applications; it has trouble rendering many more files and the
rendering is much harder to read.

------
awfullyjohn
I hope this plan includes the Rich Purnell maneuver.

~~~
gjkood
The book/movie depicts Rich Purnell using some NASA/JPL supercomputers to
verify his calculations.

Knowing nothing (or less than nothing if thats possible) about Celestial
Mechanics, considering that the technique (gravitational assist/slinghsot
maneauver???) was used in space probes as early as the 1970s, how much
computing power would be needed to do these calculations?

I guess the faster the computing resources, the earlier you would get your
solutions. But are these calculations that could be done on more run of the
mill computing hardware?

~~~
scigeek42
In the book it describes how the difficulty with the calculation came from the
fact that they were continuously firing the spacecraft thrusters (it was some
form of drive that used a constant small acceleration). Thus far most all of
our probes use short-term bursts to change their velocities. I'm not sure how
many ion-engine equipped probes we have that have needed to calculate multiple
slingshot manoeuvres.

In his interview with Adam Savage the author described how he wound up writing
his own custom code to calculate the trajectories of their spacecraft. One
could imagine that NASA would need to consider a lot more "real-world"
variables than a sci-fi author, so it is somewhat reasonable to think time on
a supercomputer could have come in handy.

------
stevecalifornia
Kudos to NASA for improving their communications with the general public. This
is exactly the kind of document I want to see-- broad yet appropriately
detailed and decorated with wonderful art.

I am excited for a future where Mars plays a similar role in science as
Antarctica. I hope that my two young daughters have the opportunity to do
research on another planet if that's what they want to do.

