Authors: Stephen Baxter
The concept seemed ridiculous, but General Dynamics had done some preliminary studies, called ‘Project Orion,’ in the early 1960s, and the presenter was able to show photographs of a small flight-test model which had used high explosives to hurl itself a few hundred feet into the air.
The technical problems were all around the high temperature flux on the rocket’s back end structure, which would have to radiate
away excess heat between explosions. And of course the system had one major drawback, the General Dynamics man said, and that was the radioactive exhaust. But that hadn’t seemed such an obstacle back in 1960 when the first Orion studies had been initiated. Then, it was thought that the unscrupulous Soviets might use this quick-and-dirty method to short-cut to space, so we had to look at it too.
The General Dynamics man joshed and wisecracked his way through his talk. When he sat down he got the biggest hand of the day.
Dana felt himself shrink into his seat.
How the hell do I follow that?
When he got to the podium Dana shuffled with his notes and foils, trying to avoid looking out over the sea of sleek suits before him. There was a spotlight on him; it seemed to impale him. It was already four thirty, and after the General Dynamics pitch the delegates had lost concentration; they were still laughing, talking.
Dana began to read from his notes. ‘Manned Mars stopover missions of duration twelve to twenty-four months are characterized by Earth return velocities of up to seventy thousand feet per second, over the cycle of mission opportunities. A promising mode for reducing Earth entry velocities to forty to fifty thousand feet per second, without increasing spacecraft gross weight, is the swingby through the gravitational field of Venus. Studies indicate that this technique can be applied to all Mars mission opportunities, and in one-third of them, the propulsion requirements actually can be reduced below minimum direct mode requirements …’
There was a ripple of reaction in the audience, a restless shifting. Dana ploughed on. He felt sweat start over his brow, around his collar.
He hurried through the idea of gravity assist. He tried to emphasize the history and intellectual weight of the idea, showing that his own computations had built on the work of others. ‘The concept within NASA of using a Venus swingby to reach Mars dates back to Hollister and Sohn, working independently, who published in 1963 and 1964. This was further elaborated by Sohn, and by Deerwester, who presented exhaustive results graphically in a format compatible with the direct flight curves in the
NASA Planetary Flight Handbook …’
It was a little like a game of interplanetary pool, he said. A
spacecraft would dive in so close to a planet that its path would be altered by that world’s gravitational field. In the swingby – the bounce off the planet – the spacecraft would extract energy from the planet’s revolution around the sun, and so speed up; in exchange, the planet’s year would be minutely changed.
In practical terms, bouncing off a planet’s gravity well was like enjoying the benefit of an additional rocket stage at no extra cost, if your navigation was good enough.
‘We have already studied the Mariner Mercury mission, which would have swung by Venus en route to Mercury. A direct journey would have been possible, using for example a Titan IIIC booster; but the gravity assist would have allowed the use of the cheaper Atlas-Centaur launch system …’
‘Yeah,’ a voice called from the audience, ‘but Mariner Mercury got canned. And there were no men on it anyhow!’
Laughter
.
Dana pressed on, brushing the sweat from his eyes. There were two ways Venus could be used to get to Mars, he said. The spacecraft could swing by Venus outbound, and use Venus’s gravity to accelerate it toward Mars. Or Venus could be used to decelerate the craft, on its way back to Earth.
‘First estimates show a mass in Earth orbit of two million pounds would be required for a mission duration of six hundred and forty days.’ Same weight as nuclear; two-thirds the trip time of chemical. ‘Thus a mission profile close to optimal is delivered, without the need for ambitious new technologies, and hence significantly reduced development costs compared to other candidate modes …’
And it’s elegant. Don’t you see that? No brute force here: no huge nuclear V-2s. Just proven technology, and elegance, and style. A little thought, gentlemen
.
‘In conclusion, it has been shown that the Venus swingby mode is generally applicable to all of the Mars flyby and stopover round trip launch opportunities, with very favorable benefits.’
Dana stepped back from the podium, retreating from the glare of the light. He was numbed, a little giddy, unable to feel his hands or face.
Seger thanked him, then opened up for questions; with a glance at his watch he signaled that these should be brief. ‘… What about guidance and navigation? Don’t you realize that you’re now talking about devising a mission profile with possibly
four
planetary encounters? – Mars, Venus maybe twice, and Earth on return? And at each encounter the accuracy of positioning will have to be of the
order of a few hundred miles, after traveling tens of
millions
. How can we navigate so accurately? Why, we haven’t yet proved we can manage a single swingby on such a scale.’
‘But we will,’ Dana insisted. ‘Remember, NASA committed to the lunar-orbit rendezvous mode for Apollo – which required a rendezvous a quarter of a million miles from home – before a single space rendezvous had been demonstrated.’
There was some muttering at this.
Hardly a valid comparison
.
‘What about the design constraints? Near Venus the sunlight is four times hotter than at Mars, so you’ll be sacrificing payload space for a cooling system that will be dead weight at Mars. And there’ll be problems with the increased level of radiation coming from the sun …’
Dana tried to answer –
I’ve incorporated spacecraft design modifications into my weights analysis, and …
But he was all but drowned out by the noise of an audience which had little interest in him.
Now Hans Udet stood up, and a hush gathered. Udet said precisely, ‘On what basis have you arrived at your figures? I am aware of the preliminary analyses of the complicated mission classes you describe. I am aware of no detailed analyses which show the savings you claim.’
Dana began to stammer out a reply.
But our understanding of spacecraft systems has advanced since those early studies, and with the figures I have compiled, we can now show that –
‘These results are false.’ Udet glanced around at the audience, tall, aristocratic, in control, charming even now. ‘This is obvious. The figures we are shown are based on unstated suppositions. The speaker doesn’t know what he’s talking about. It may be incompetence, or malice, whatever. We should not expend further energy on this red herring.’ He sat down, his back ramrod-straight.
There was an uncomfortable stirring in the audience, some nervous laughter.
Bert Seger got to his feet, quickly thanked Dana, and turned away from him.
Udet’s words were incredible to Dana.
Such accusations should not be made, in such fora as these, or beyond. It is – uncivilized
. Somehow, though, now that it had happened, there seemed a certain inevitability about it all.
Of course, I have been rejected. But this isn’t about logic, or engineering, or science
. It was because he’d gone outside the hierarchy, the formal channels.
This really is about power. In-fighting. It’s possible Udet is even sincere. Maybe he
really does think I’ve cooked up these numbers, that I’m just infighting for Langley
.
Dana gathered together’ his foils, clumsily, and got off the stage.
The lights went up, and the conference room was quiet. Bert Seger got to his feet and began stalking along the stage, eyeballing the delegates as if challenging them, his hands on his hips.
‘I’ve heard a lot of good things today about the nuclear mode,’ he said. ‘And I’ve heard nothing else today, frankly, that makes a hell of a lot of sense to me in comparison.’ He glared at the audience. ‘Now, I have to say that I think we can do this. I think we do indeed have a “Kennedy option” to present to the President. And I’d like to hear now what sonofabitch thinks nuclear isn’t the right thing to do.’
There was a little more to and fro. Wernher von Braun got to his feet to make a brief statement commending the nuclear option. Then one of the chemical option presenters from Houston got up, and graciously conceded defeat to the guys from Marshall.
Seger closed the meeting. ‘Gentlemen, I want to thank you here for all the work you’ve done. I think we’ve found a way we can work together and do this thing. I think we’ve worked out how we’re going to Mars.’
He started to clap, then; and the hall joined in, applauding themselves for their achievement.
All but Dana. At least he could resist that much.
The Germans had won again.
Seger might be right. Perhaps we’ve made a historic decision that will, indeed, take men to Mars within my lifetime. But it’s wrong. I know it’s wrong
.
Anyhow, he thought, it’s still possible this huge mission will never be funded. Perhaps Nixon will choose to build the Shuttle. Or nothing at all.
Nothing at all.
The applause went on, until the delegates started to cheer themselves.
FUTURE OF NASA
Present tentative plans call for major reductions or change in NASA by sharply reducing the balance of the manned space program and many remaining NASA programs.
I believe this would be a mistake.
1)The real reason for reductions in the NASA budget is that NASA is entirely in the 28% of the budget that is controllable. In short we cut because it is cuttable, not because it is doing a bad job or an unnecessary one.
2)We are being driven, by the uncontrollable items, to spend more and more on programs that offer no real hope for the future: welfare, interest on National Debt, Medicare, etc. Essentially they are programs not of our choice, designed to repair mistakes of the past.
3)There is real merit to the future of NASA and to its proposed programs. Skylab and NERVA particularly offer the opportunity, among other things, to secure substantial scientific fall-out for the civilian economy at the same time that large numbers of valuable (and hard to employ elsewhere) scientists and technicians are kept at work on projects that increase our knowledge of space. It is very difficult to reassemble the NASA teams should it be decided later, after major stoppages, to restart some of the long-range programs.
4)In response to our pressure NASA has reduced its requested development budget for the next several fiscals by
half
.
5) Apollo 14 was very successful from all points of view. Most important is the fact that it gave the American people a much needed lift in spirit (and the people of the world an equally needed look at American superiority). Announcement now that we were canceling or severely diminishing the US manned space program would have a very bad effect. It would be confirming in some respects a belief that I fear is gaining credence at home and abroad, that our best years are behind us, that we are turning inward, reducing our defense commitments, and voluntarily starting to give up our superpower status, and our desire to maintain world superiority.
America should be able to afford something besides increased welfare …
Handwritten addendum
: I agree with Cap. RMN.
Caspar W. Weinberger, Deputy Director of the Office of Management and Budget, Memorandum to the President, August 27, 1971. White House, Richard M. Nixon, President, 1968–1971 File, NASA Historical Reference Collection, NASA Headquarters, Washington DC
Ben Priest swung through Glendale and then turned north on Linda Vista, heading past the Rose Bowl. His hired car was an antique Dodge, and its heating was malfunctioning; outside it was a cold December day, and York alternately baked and shivered.
‘This seems a long way out of Pasadena,’ she remarked.
He grinned. ‘Yeah. Well, they used to test rocket engines here. Everyone thought the place would be dangerous, so they built it way the hell out there, in the arroyo. And then they built a sprawling, expensive suburb all around it.’
York saw that office buildings filled the arroyo; some of them were drab boxes, but there was also an imposing tower of steel and glass.
There were cars parked for a quarter mile along the road leading to JPL, and the street outside the press center was nearly blocked by TV vans.
There was a guard at the JPL entrance; he waved them into a parking lot. It seemed to York that pretty much every space was taken.
They got inside quickly; the cold seemed to be deepening. Priest guided her through corridors littered with computer cards and print-outs. Close-up photographs of the Moon’s surface were casually framed and stuck on the walls. JPL seemed a strange hybrid; this might have been any office complex anywhere, York supposed, except that people were younger than the average – and not one of them wore a suit, or a tie – and there was a
lot
of hair about, bristling above yellow Smile buttons. Some of the women even wore hot pants. But at the same time the place didn’t have the ragged, laid-back feel of a college; there was too much urgency for that. There was a sense that things
happened
here.
She remarked on how full the car park had been.
Priest said, ‘You should have been here a week ago, when the first pictures began coming through from Mars. You couldn’t move for press guys, and VIPs, and politicos, and science fiction writers – anybody and everybody who could scrounge a pass.’ He laughed. ‘You should have seen their faces, when all we got back was a picture of the dust-storm.’
It was odd to be with Priest again. A
blast from the past
. She hadn’t seen him for more than a year, and she’d been surprised
when he’d come through on his old promise to bring her here to see the results from Mars come in. He hadn’t changed, as far as she could see: slim, dedicated to his job, easy-going, intelligent.