Margaritifer Basin (Margaritifer Trilogy Book 1) (24 page)

He sighed aloud and rubbed his forehead. “Okay, so then we
aerobrake into a better orbit.”

Gabe shook her head. “Jeff, it took the MRO five months to
aerobrake into its final orbit. We won’t have months, we’ll have days; two
weeks at best.”

Jeff groaned. “Oh, fuck me.”

Gabe frowned. “Uh, no, I don’t think so.”

“Sorry, figure of speech.”

“I’d prefer you used a different one.”

Jeff rolled his eyes. “I stand admonished. Okay, so we need
to do a powered insertion.”

Gabe shrugged.

“Can we send a second booster along with it? Or just make
that one bigger?”

“It would have to be twice the size, or you’d need a second
booster of equal size.”

“Oh god.”

“Yes. Um, that would require another launch, another Falcon
Heavy. But there’s an even bigger problem; now you’re up to 230,000 pounds,
minimum. Add to that 32,500 pounds for the burnout mass of the EDS and… you
can’t get there from here. You’d need 300,000 pounds of fuel for the TMI, and
you don’t have it. At most you have 260,000.”

“Ah Jesus! Gabe, there has to be a way to get home.”

Gabe smiled. “Jeff, it’s obvious that you’ve read most of
the various manned Mars proposals that are floating around. And, as such,
you’ve probably noticed that many of them concluded with something like ‘And we
leave Mars and go home’, footnote: details to follow. Getting to Mars is easy;
it’s been done lots of times. Landing stuff on Mars is not that hard; that’s
also been done many times. But getting back from Mars? That’s never been done,
and for good reason.
That
is the hard part. That, to use your
expression, is the part for which there is no part. And I don’t know about you,
but if we can’t get back, I’d rather prefer not to go.”

Jeff nodded. “Well, I won’t argue that. I’ve read a couple
of the suicide mission proposals.” He shook his head. “There are some seriously
demented people out there.”

“Yes, and I’d rather not be one of them.”

“Yeah, now I understand why there’s so much talk of
in
situ
manufacture of the return trip fuel.”

“Correct, but that too is not without its problems, not the
least of which is, how do you get all that fuel off Mars and into orbit?”

“Just out of idle curiosity, what would it take to launch
115,000 pounds from Mars?”

“I don’t know, there are a lot of variables and unknowns.
Um, but just using a ballpark figure of say, orbital velocity at 100 miles in
altitude, and ignoring gravity and air resistance, you’re looking at a minimum
Delta-V of, um, about 3,460 meters per second. That would take another 260,000
pounds of fuel. So, I don’t know, call it 300,000, minimum, plus payload.”

“Good god, that’d take forever to manufacture.”

“Yes, you’d have to launch everything for
in situ
in
this next launch window.”

“Can’t be done.”

“No.”

“Anything left in the cupboard?”

“It’s looking rather bare. There’s just not enough time.”

“Son of a bitch, there has to be a way to do this.”

Gabe smiled. “You know, I think you’re spending too much
time around Abby. You’re starting to talk like her.”

“Sorry.” Jeff stared at all the drawings on the walls and
thought for a moment. “Hey, what if we put the return booster in a lifting
body, so we have more control of it during the aerocapture? And, I might add,
by that time we will have already had some experience with lifting bodies in
Mars atmosphere. At least the first cargo ship, maybe both.”

Gabe’s eyebrows went up. “Hmmm, that could work, though you
still have the problem of trimming the orbit.”

“Okay, um, how about we split the difference.”

“Huh?”

“We send along a second booster about the size of a Centaur.
Then, once it’s captured we jettison the aeroshell and heat shield and use the
Centaur to trim the orbit, quickly. Could we get that mass to Mars?”

She slowly nodded. “Yes.” She smiled. “That might just
work. It’d still require another launch, but just of the Centaur. You could do
that with an Atlas V.”

“Uh huh.” Jeff sat back in his chair and sighed deeply.
“Work on it. That may just be our answer.”

“Okay. But, there’s still the matter of fuel for the SPS.
Oh, and also the lander.”

“What are we talking, about 20,000 pounds?”

“Yes.”

“Well, we might be able to squeeze that into a Delta IV
Heavy and do it in one shot.”

“You’ll also need a cruise stage that’s big enough to get
it into orbit.”

“Oh crap, there’s no end to this. Alright, well, juggle all
the manifests and see if there isn’t some way that we can squeeze that stuff,
or at least part of it, in somewhere else. We have to have some spare payload
somewhere. Work on it.”

“Okay.”

 Jeff stared at the table and thought for a moment. “Um,
there is one other problem with this scenario.”

“What?”

“Well, assuming we follow through with our plan to bring
home a real live Martian, and a minimum of six months development time in
gravity, that date change cuts our window for conception down to two and a half
months. That’s not a whole lot of time.”

Gabe frowned. “Jeff, I’m a physicist, not an obstetrician
or pediatrician. I can tell you how to get us there and maybe how to get us
back, but what you’re talking about is way outside my field. Besides, you know
full well that I’m not real crazy about the idea to begin with. I’ll go along
with it, I’ve told you that, and I mean it, even if the, uh, chosen one turns
out to be me.” She grimaced and swallowed hard. “But, don’t look to me for
solutions on that matter.”

Jeff smiled apologetically, and nodded. He reached across
the table and took her hand. “Yeah, sorry, you’re right.”

She nodded.

“Okay, you just go right on catching my mistakes, and we’ll
be fine.”

“I’ll try.”

“What were those dates again?”

“March 14, October 12.”

“Alright, get those to Chrissie and have her adjust the
flight plan accordingly. We’ll probably have to bump something from the surface
exploration plan but what the hell, it’s probably too ambitious anyway. And, as
you note, just getting there and back is the important part.”

She squeezed his hand. “You’ll get no argument from me on
that.”

“And in the meantime, find us a return booster. That could
be a long lead-time item, so we’ll need to get it started soon.”

Gabe nodded. “Right.”

Jeff gazed into her eyes and smiled softly. “Now do you
know why you’re here?”

She returned the smile and nodded. “Yes.”

“Think you’d be doing this in some post-doc research job at
Caltech?”

Gabe shook her head. “No.”

“Okay then. Are we done?”

“Not quite.”

Jeff groaned, “Oh god, what else?”

“After this first series of launches, you’ll be broke. What
are we gonna do?”

Jeff smiled. “Raise more money. Like launch weights and
Delta-Vs, there’s no other option.”

Gabe smiled and nodded.

Abby’s voice rang out from the theater in Wrentham House’
lower level, “Would you two give it a rest and get in here? We’re supposed to
be having a party.”

Gabe frowned, “What is she yakking about now?”

“I dunno.” Jeff yelled back, “On our way.”

“The big day,” said Gabe as she and Jeff walked toward the
theater.

Jeff shook his head, “God I hope it works. Everything
depends on it.”

She took
his hand and squeezed it, “It’ll work.”

#

Eight and a half months earlier
NASA had finally managed to get the Mars Science Laboratory,
Curiosity
,
off the ground and on its way to Mars. It was now just a couple hours from
landing. Jeff’s entire plan depended upon utilizing the MSL’s Entry, Descent
and Landing – or EDL – technology. If the MSL failed to make it to the surface
in one piece, Jeff’s dream of going to Mars might well be over.

It was shortly past 10:30 when Jeff
stepped into the dimly lit theater and looked up at the twelve-foot screen.
“Nice picture.” The entire screen was filled with a close-up view of Mars’
southern hemisphere. It was late afternoon on the red planet, and the surface
features were clear and bright. “What are we looking at?”

Abby looked at him a bit
flabbergasted, “It’s Mars, doofus!”

“Really? You sure?” He gave her a
mildly sarcastic grin. “Chrissie, what is this?”

Chrissie glanced up from the
console at the back of the theater. “Time lapse of Viking II’s approach to
Mars. There’s no feed yet from JPL. They’ll begin their live stream in about an
hour. I think the MRO will be in a position to see the MSL landing. That’d sure
look cool on the HiRISE camera.”

“That it would.”

Gabe nodded. “The HiRISE got a shot
of the Phoenix lander on chute, they should be able to get this one, maybe.
They timed it about right. The MRO is in a polar orbit and makes exactly twelve
sun-synchronous orbits a day – Mars time. And on the daylight side it always
crosses the equator at exactly 3:00 p.m. LMST – Local Mean Standard Time –
which is almost exactly when the MSL is scheduled to land.”

Susan walked up to them with a
couple mugs. “Coffee? It’s fresh.”

Jeff took a mug. “Yeah, thanks.”

“And there’s a bunch of food on the
table. I also put some champagne on ice, just in case.”

“Hey, that’s great. Thanks. The
power of positive thinking?”

Susan laughed, “Something like
that. Those images aren’t from the MSL?”

Gabe shook her head. “No. The MSL
doesn’t have a camera on the aeroshell. The first MSL images we should see will
probably be from the hazard avoidance cameras, Hazcams, shortly after landing.
They are small black and white cameras that are mounted over the wheels. It’ll
probably be tomorrow before we see the first images from the MARDI.”

“What’s the MARDI?”

“Mars Descent Imager. It’s a down
looking color camera located beneath the rover that will start taking pictures
at about eight frames per second as soon as the heat shield is jettisoned.
They’ll use its pictures to figure out where it lands.”

“They don’t know where it’s going
to land?”

“Oh, they know within 10 kilometers
or so. But in comparing the MARDI images with images of the area from the MRO’s
HiRISE camera they’ll be able to pinpoint its location. And they need that in
order to tell it where to go and what to do with itself. But that’s also why
they would like to image it with the HiRISE as quickly as possible. That will
also tell them right where it is.”

“How will they manage to have the
MRO taking pictures of the landing? Can they adjust its orbit?”

“Yes, but they probably didn’t need
to, they just adjusted the MSL’s trajectory to schedule a landing when the MRO
would be making a pass over the landing site.”

“And that will be what time here?”

“The landing is scheduled for 2:50
p.m. LMST, a little less than three hours from now, though it will be another
fourteen minutes before we see it, about 1:32”

“Is that when we plan on landing?
Mid-afternoon?”

Jeff shook his head. “Wouldn’t be
my first choice. We’re going to have a lot of work ahead of us immediately upon
arrival. It’ll be a long day. An early to mid-morning arrival would give us a
lot more daylight to get some things done.”

“Like what?”

“Well, the rovers will be able to
relocate some things and even make some simple connections, like electrical and
various tank connections to the Sabatier reactor, but they won’t be able to
dock the habs, since the docking adapters will have to be unpacked; we’ll have
to do that ourselves. Further, most of our provisions won’t be on wheels, and
we’ll have to locate those and manually winch them onto the rovers and haul
them to the station. We can temporarily setup housekeeping in the Genesis
trailer, but it’s only fourteen feet long and eight feet in diameter, not
including the air lock, so it’s a bit cozy for four. The sooner we can get the
station assembled, the more comfortable we’ll be. So the first few days will
likely be pretty busy.”

“Sounds like it.” Susan frowned.
“Does the trailer have a bathroom?”

Jeff grinned. “Um, define…
bathroom.”

“Uh oh.”

“Yeah, it has, uh, facilities, but
not exactly a, um… bathroom.” He chuckled. “Eh, it’ll just inspire y’all to
work a little faster. Chrissie, where’s the MSL?”

“5,430 meters per second, about
48,900 kilometers altitude, two and a half hours to go. Five by five and in the
pipe,” she grinned.

Jeff glanced back at her and
winked, “Now you sound like an astronaut.”

Chrissie smiled broadly and gave
him a thumb up.

Gabe stood next to Jeff, looking up
at the screen. “Wow. Just think, if all goes well four years from now we’ll be
seeing that view out the front window.”

“Yeah, that will be something.
Chrissie, what’s the time delay?”

“I don’t know. Right now Mars is,
um, let me see, 1.66 AUs from Earth, so…”