QUESTION:
My question deals with the ability to record and or
communicate in "real time" with future missions. I realize
there is a signal delay, but it seems that if we can strap a
camera on the side of a rocket launching satellites from
earth recording the full duration from lift off to
deployment, why can't we do the same for a probe landing on
Mars?

Even better, have two or three "inexpensive" communication
satellites that detach from the Lander portion of the
mission before entry into the atmosphere that help the
lander triangulate its descent and trajectory. In doing so,
micro satellites could not only help land the mission, but
could enhance communications windows for the mission at hand
and for future missions. Not having to scope out the skys
for earth to come over the horizon, communication could be
almost constant.

It seems that we are putting the cart before the horse. It
has taken us years to deploy satellites into Earth orbit for
everything from communications to GPS and other wonders,
maybe we need to take a step back and look at this from a
global perspective, a Mars global perspective that is. In
order to SAFETLY land humans and RETURN them to EARTH,
shouldn't we be thinking about the global needs of
undertaking such a task? Geo-stationary satellites, GPS,
communications relays?
I recently read an article about, I believe, a NASA
scientist who has proposed Micro-satellites. In swarms,
these devices can work together while orbiting a planet to
set up communications arrays, gps, and even effect repairs
to each other in the event of failures.

I realize that NASA is doing things 'faster and cheaper' and
along with Technology Sharing, encouraging major
corporations to help finance in return for future profits or
technology, but let's be a little more broad sighted. If we
are to have Mars as our focus, and our long-term focus being
that we will one day colonize the planet, then why not lay
down the "Space Infrastructure" to do so effectively,
safetly, and efficiently?

Just as every state must compete for federal highway funds,
why not have every Mars project do a little something for
the greater good of all future projects?
Tag-along projects could include the communications devices
I have suggested, but would also enhance and possibly insure
the success of future missions, which could then make use of
this newly laid "ground work in the sky".

Another alternative is to require missions be packaged
together and work in unison. If Global Surveyor would have
been positioned near the entry area of the Polar Lander and
operations were coordinated, who knows, we may have captured
a snap shot of the Polar Lander blowing up, or of the chute
opening. And if the two were in communication with each
other, maybe the Polar Lander would have made it through.

I realize that this is all speculation, and believe me as a
US citizen, taxpayer, and an inhabitant of Planet Earth I
would like nothing more than for NASA to succeed on every
mission. I guess what I am suggesting is even more of a
unified spirit, not only for NASA and the aerospace
industry, but WITHIN NASA and the different programs.
It has been said that true genius is the ability to take
seemingly unrelated fields and combine them into a practical
solution.........I hope that we can do this in the future.

ANSWER from Rich Hogen on December 17, 1999:
You have good ideas, but you're preaching to the choir and some of your
ideas are not quite workable.  NASA has thought of all this and has
evaluated options.  Remember, the "right solution" from a purely engineering
standpoint is never the "right solution" when you throw budget and politics
and the (vehement) desires of the science community (who control the
payloads) into the mix.  Also, bear in mind that a very large percentage of
any mission is the launch vehicle, so putting anything into Mars orbit, even
small satellites which are themselves cheaper than anything ever flown, is
still very expensive, so there's a point of diminishing returns.  That's why
NASA has the various X-projects, to help further the development of advanced
launch vehicle options to reduce that launch cost.  Launch vehicles are a
major issue.

When you suggest that missions be packaged together you start to deviate
from the faster, better, cheaper paradigm, which is to do the opposite --
have missions that contribute to an overall program of exploration but which
do not ruin other missions if they fail, which is always possible.  You
should also understand that sometimes things are uncontrollable.  Mars
Global Surveyor is indeed in a polar orbit, but it's flying so fast that it
passes over any one point on the surface (horizon to horizon) in about ten
minutes, whereas entry, descent and landing is a fifteen minute process.
Further, even though MOC is the highest resolution camera ever flown to Mars
(or elsewhere?), it simply does not have the resolution to spot MPL, which
is too tiny (within a single pixel) and moving too quickly and through an
unpredictable atmosphere to track.  Even a giant billion dollar military spy
satellite would not be able to accomplish a real-time detailed tracking of
such an event.  We were able to take images of Phobos with MGS, and that was
no small feat, but Phobos is huge compared to a spacecraft, and its orbit is
better known than is the trajectory of a spacecraft entering a variable
atmosphere, although it wasn't known perfectly.

As for "strapping on" extra hardware, bear in mind that in order to save
costs on launch vehicles these spacecraft are designed to fully occupy the
volume and mass envelope of smaller, cheaper launch vehicles (Deltas).  Any
additional mass and volume _will_ take away from something else, something
that probably already has a critical engineering or scientifc purpose, OR
will drive you to the next larger launch vehicle and another huge chunk of
money.  I personally think we should be strapping multiple tiny digital
cameras on our spacecraft because it'd be really cool to see the spacecraft
in space, doing it's thing.  Having experienced the nightmare solar panel
problem on MGS, I think that a few tiny cameras would have helped
dramatically with the diagnosis of the problem.  So it isn't just a gee-whiz
thing, although I'm all for gee-whiz, too.

But bear in mind that cameras require some electronics, data handling and
storage, telecomm bandwidth and cabling, all of which must work in the
incredibly harsh space environments, and they cause RF interference.  No
spacecraft hardware is ever trivial to add.

I often see letters like yours, from concerned pro-space citizens saying,
"why not just do <this> or <that>?", and these letters always reveal a
fundamental lack of understanding of the scientific, engineering and
political problems involved.  Remember, there is a reason it requires
hundreds or even thousands of people to accomplish these missions, many of
whom have advanced degrees in all kinds of specialties.    I like to think
of space exploration as the modern equivalent of building the pyramids, but
without the slavery or the despotic unified control.  Nothing is trivial in
space exploration, and compromise is fundamental to the process as a whole,
so individual missions might not seem to make sense when you think about
what you want to get done, but they usually make sense in terms of what's
realistic, feasible.

Finally, I need to point out that NASA's current mars exploration program
does NOT have as its goal a human mission to Mars.  We are still in the
learning stage -- at every turn Mars is revealing its complexities and new
mysteries.  We need to learn a lot more with science missions before we can
begin building a realistically safe human mission to Mars.