Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT_ZIP/spacedig/V09_3/V9_301.ZIP/V9_301

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Subject: SPACE Digest V9 #301

SPACE Digest                                      Volume 9 : Issue 301

Today's Topics:
                  Re: Sanger
            Re: NORTHERN LIGHTS!!
                  Re: Sanger
              Re: Babies born in space.
Discovery's return-to-flight photographs record many firsts (Forwarded)
         Re: Space station & stone-age units
           Re: NASA FY-1990 Budget Request
          Re: E'Prime and news about Thiokol
----------------------------------------------------------------------

Date: 15 Mar 89 14:09:14 GMT
From: thorin!lhotse![e-mail]  (James Symon)
Subject: Re: Sanger

In article <[e-mail],
[e-mail] (Paul Dietz) writes:
> . . . Sanger would use turboramjet engines to propel a winged
> first stage to Mach 5, at which point a LOX/LH2 propelled second stage
> -- either an unmanned expendable cargo rocket (like Pegasus) or a
> reusable winged manned vehicle -- would be released to ascend to
> orbit.

I would think that the greatest advantage an air launch would have
over ground launch would be initial altitude not initial speed. Mach 5
is pretty tough to achieve with a cargo vehicle and is only about 20%
of orbital speed so why bother getting up to that speed with your
launcher/first stage? Sounds like a lot more trouble and expense than
a traditional first stage, even after initial development costs.

Getting up to good altitudes might be useful, though, to get above all
that air resistance. Let the air help you instead of fighting you.
Design your aircraft first stage to achieve maximum altitude and
forget about speed except as it comes along as a free bonus.

Is the battle against high density air also a small percentage of the
effort and not worth it? How much of the work of an expendable first
stage could be done with an aircraft without significant design
innovation? Would effort be more profitably expended in going for
altitude or speed? What's the d/d$?

jim
[e-mail]
{decvax uunet}!mcnc!unc!symon

------------------------------

Date: 15 Mar 89 16:34:55 GMT
From: sunkisd!concour![e-mail]  (Patrice Scattolin)
Subject: Re: NORTHERN LIGHTS!!


>
>Will this solar activity be any danger to the people or equipment in
>the shuttle?

    I don't know aqbout that but what I know for a fact is that
the magnetic storm causing the Northern Lights is being blame for
a province wide power failiure that lasted around 7 to 8 hours. Apparently
the change in magnetic fields induces curents in the transmission lines
making the voltage fluctuate from 736 KV to 700 KV to 800 KV and resulted
in equipement failiures.

    They are pretty but they are trouble!



_____________________________________________________________________
Patrice Scattolin.        Concordia University, Montreal Canada
[e-mail]
"I live so far North that Santa lives two blocks down the street."

------------------------------

Date: 15 Mar 89 22:47:52 GMT
From: asuvax!enuxha![e-mail]  (Norman C. Kluksdahl)
Subject: Re: Sanger

In article <[e-mail]>, [e-mail] (James Symon) writes:
> In article <[e-mail],
> [e-mail] (Paul Dietz) writes:
> > . . . Sanger would use turboramjet engines to propel a winged
> > first stage to Mach 5, at which point a LOX/LH2 propelled second stage
> > -- either an unmanned expendable cargo rocket (like Pegasus) or a
> > reusable winged manned vehicle -- would be released to ascend to
> > orbit.
>
> I would think that the greatest advantage an air launch would have
> over ground launch would be initial altitude not initial speed. Mach 5
> is pretty tough to achieve with a cargo vehicle and is only about 20%
>
I have done some back-of-the-envelope calculations to check out the
advantages of speed at release of the orbital vehicle.  (Note:  these
are only rough calculations, intended only to demonstrate a point).

In all cases, it is assumed that the payload is released at an altitude
sufficiently large to neglect most air frictional effects.  (Note 2.  This
perhaps implies use of rockets to provide the final acceleration of the
carrier vehicle.)

Assuming Isp = 400 (which gives exhaust velocity of 4000 m/sec)

   Mach # at launch       Mass Ratio
         1                  5.27
         2                  4.90
         3                  4.56
         4                  4.24
         5                  3.96
         6                  3.68
         7                  3.43
         8                  3.19

Mass ratio is the ratio of fuel and structure at launch to the mass of
the structure delivered to orbit.

A few important features stand out here.  First, if you can get to
altitude where air resistance is negligible, the usable payload becomes
a large fraction of the launch weight ( 19% - 31% ).  Of course, you
have to then figure what fraction of the vehicle can actually be devoted
to payload and what is structural weight.  Second, like all chemical
rockets, trade-offs are an integral part of the game.  Accelerating the
'aircraft' carrier to a decent Mach number will eat fuel, which means that
the structural weight of the carrier becomes non-negligible.  Higher Mach
numbers require technology like air-turbo ramjets or such, which aren't
exactly off-the-shelf items, or rockets, which means dual power sources
and more parasitic weight.  In addition, atmospheric heating of the carrier
will necessitate some form of heat shielding, which increases the parasitic
weight.  Counting the carrier, the usable payload fraction is quickly
diminishing to single digit percentages (or less!!).

As with all rocket design, the final configuration will inevitable be a
compromise.  Still, air launch does promise something--I read that OSC's
Pegasus gains about 15% in usable payload by air launch at Mach 0.8.
Just imagine the gain if they had an XB-70 to launch from... :-) :-) :-)


**********************************************************************
Norman Kluksdahl              Arizona State University
            ..ncar!noao!asuvax!enuxha!kluksdah

standard disclaimer implied

Useful criticism always appreciated.  Senseless flames always discarded.

------------------------------

Date: 13 Mar 89 23:11:51 GMT
From: asuvax!mcdphx!mcdchg!ddsw1!corpane![e-mail]  (John Sparks)
Subject: Re: Babies born in space.

In article <[e-mail]>, [e-mail] writes:
>
>    I saw a report recently that had a Get-Away-Special mission that was
> sending up half of a set of ``identical'' chicken eggs, the other half staying
> on the ground as a control group. While not exactly human development, I'd
> say it's certainly a first step in such research.
>
> Alan M. Carroll          "And then you say,

Yes, I heard about this recently. I believe they went up on todays launch
of Discovery [today is March 13, 1989].

But what I wonder about in these experiments is how do they know that the
results they get back on the space eggs are the result of the micro-gravity
environment and not some damage caused by the hi-g blast off and shaking?

If you hatch scrambled eggs do you get scrambled chickens? :-)




--
John Sparks      // Amiga  |  {rutgers|uunet}!ukma!corpane!sparks
               \X/  UUCP   |  >> call D.I.S.K. @ 502/968-5401 thru 5406 <<

Chicken Little only has to be right once.

------------------------------

Date: 15 Mar 89 16:53:10 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: Discovery's return-to-flight photographs record many firsts (Forwarded)

Charles Redmond
NASA Headquarters, Washington, D.C.                March 14, 1989

James Hartsfield
Johnson Space Center, Houston


RELEASE: 89-

DISCOVERY'S RETURN-TO-FLIGHT PHOTOGRAPHS RECORD MANY FIRSTS


     Earth observation photographs taken by Discovery's crew
during America's return to piloted space flight in 1988 were
among the clearest in more than 20 years, and they captured a
variety of environmental conditions.

     Included in the astronauts' photography from the September
1988 mission is a photograph showing at least a 1 million square-
mile smoke cloud over South America's Amazon River basin and, in
Africa, evidence of flooding in areas that have experienced a
lengthy drought.

     Due to an unexpected improvement in atmospheric clarity over
the Northern Hemisphere, the Discovery crew could distinguish
ground details about 700 miles away from their spacecraft, much
farther than has been normal for Space Shuttle flights.
Visibility over the Northern Hemisphere during STS-26 was the
best since the 1960s Gemini Program flights.

     In total, the crew took 1,505 photographs of Earth during
the 4-day mission.  Discovery was launched into an orbit that
kept it above only the tropical and subtropical regions of
Earth.  That orbit took the spacecraft over about half of Earth's
surface, covering parts of 122 nations and regions that hold
about 75 percent of the world's population.

     Photographs show a dense, white smoke cloud, the result of
tropical forest, pasture and croplands being cleared and burned,
completely obscuring the ground over much of South America's
Amazon River basin.  If placed over the United States, the same
cloud would cover an area of the country more than three times
the size of Texas.

     It is the largest and thickest accumulation of smoke ever
photographed by astronauts, much larger than the previous largest
smoke cloud photographed by astronauts over the same region in
1984.

     STS-26 also photographed smoke clouds over Sumatra and
Borneo, Indonesia, Madagascar, eastern Africa, northern Australia
and Bolivia.  Some photographs show apparent irrigation features
in the tropics -- in areas that normally receive 100 inches of
annual rainfall.

     In Africa, the "green line" of vegetation that generally
marks the southern boundary of the Sahara Desert had moved the
farthest north it has been in astronaut photography since 1965.
Also, standing water was photographed in the Sahara.

     For the first time in Shuttle history, Africa's Niger river
was photographed in full flood and out of its banks.  Photographs
of the Blue and White Nile rivers also showed evidence of recent
flooding.

     Throughout eastern Africa, the landscape was tinted with
green, a condition never before seen in this region during the
Shuttle program.  Still, Africa's Lake Chad and Lake Nasser, two
lakes that have long been studied by space photography, were at
the lowest levels ever photographed by astronauts.  Since 1960,
Lake Chad's surface area is estimated to have declined by more
than 90 percent.

     The extreme atmospheric clarity over the Northern Hemisphere
during the mission was due, at least in part, to the absence of
major global duststorms.  Duststorms of million-square mile
dimensions over northern Africa, even extending halfway across
the Atlantic Ocean, were photographed during 1984 and 1985
Shuttle flights.  But no such African duststorms were seen during
STS-26, nor were major duststorms observed elsewhere.

     A lack of recent major volcanic eruptions, which cause dust
in the upper atmosphere, also may have contributed to the extreme
clarity.

     As a result, the STS-26 photographs captured details not
usually seen in Shuttle photography: for the first time, an
aircraft was photographed generating a contrail; individual
buildings could be seen in the Canary Islands; a line of
electrical transmission pylons was seen in southern Sudan; and
oil platform flares were seen in the Gulf of Campeche.  STS-26
also photographed the effects of Hurricane Gilbert on the Mexican
Gulf Coast and five volcanoes with signs of eruptive activity.

     Earth photography from the Space Shuttle is managed by the
Space Shuttle Earth Observations Office at the Johnson Space
Center.  The office trains Shuttle crews in Earth photography,
selects targets for photography for each mission and analyzes the
resulting photographs.  In addition, research is conducted by
specialists in environmental sciences, biology, climatology,
geology and other fields using data obtained with Shuttle
photography.

------------------------------

Date: 15 Mar 89 19:36:39 GMT
From: vsi1!v7fs1![e-mail]  (Mike Van Pelt)
Subject: Re: Space station & stone-age units

In article <[e-mail]> [e-mail] (MacLeod) writes:
>A month or so ago I made the heretical statement that the USA ask for
>technical specs for Soviet docking and fastening interfaces and adopt them
>as an international standard.   Nobody commented on this.  On second
>thought, though, there a third set of standards, those used by the ESA.

I didn't see that message, but it certainly sounds like a good idea.
It's kind of like the IBM PC -- it may not be the best, but there
are more of them out there than there are of everything else
put together.  And certainly the Soviets have more docking experience
than everyone else put together.
--
Mike Van Pelt            Video 7            ...ames!vsi1!v7fs1!mvp
There are  no perfect  power sources.   There is no  such thing as
100% perfect safety.  There is no such thing as zero environmental
impact  short  of the entire human race committing  mass  suicide.

------------------------------

Date: 15 Mar 89 21:58:50 GMT
From: agate![e-mail]  (William Baxter)
Subject: Re: NASA FY-1990 Budget Request

In article <[e-mail]>, willner@cfa250 (Steve Willner P-316 x57123) writes:
>
>Here is the NASA budget request for fiscal year 1990 (beginning
>October 1, 1989).

>             NASA FY 1990 BUDGET SUMMARY
>            (Millions of Dollars)
>
>        NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

>Shuttle Production & Capability Development  1128.2     1305.3 (total)
>Space Shuttle Operations                     2305.2     2562.7 (total)

>Expendable Launch Vehicles                     85.5      169.5


Is it any wonder that the dream is dead at NASA?


William Baxter

ARPA: web@{garnet,brahms,math}.Berkeley.EDU
UUCP: {sun,dual,decwrl,decvax,hplabs,...}!ucbvax!garnet!web

------------------------------

Date: 14 Mar 89 23:26:20 GMT
From: mailrus!wasatch!uplherc!esunix![e-mail]  (Bob Pendleton)
Subject: Re: E'Prime and news about Thiokol

From article <[e-mail]>, by [e-mail] (Jim Bowery):
> I'm curious as to how E'Prime gets away with saying that out of 17 test
> flights none have failed when Bob claims that the MX booster produced by
> Thiokol has killed several people.  Were the ground tests a disaster followed
> up by a streak of good luck?

It was a manufacturing accident. While pulling the casting core out of
a motor something happened. Some how the crew running the operation
wound up un the bunker with the pulling equipment. Somehow the motor
fired. All the men on the crew were killed. Morton Thiokol settled out
of court. They also paid some large federal fines for safety
violations.

What it comes down to is that no one seems to know what happened
because all the equipment that was supposed to be monitoring the
operation was broken. Based on the little that was in the local papers
all the safety equipment was broken and had been for some time. It
seems the Air Force contract required the equipment to be their, but
didn't require it to work. So Morton decided to risk the lives of the
crew to save the cost of a repairs.

> What sort of quality controls were imposed by
> Thiokol on the flight-bound boosters to make them so reliable?  What
> additional safety measures were imposed by the Air Force?  Since a decent
> solid rocket inspection system costs a small fraction of a launch (only about
> $2million amortized over many launches) I would guess E'Prime could afford
> to put all Thiokol's boosters through their own inspections.

I don't know. I believe that the Air Force refused delivery on some
motors. Not all the MX motors that were manufactured for flight
testing were actually launched. At least once the Air Force stopped
progress payments on MX to Morton Thiokol. They were not resumed until
acceptable motors were shipped.

            Bob P.
--
-              Bob Pendleton, speaking only for myself.
- UUCP Address:  decwrl!esunix!bpendlet or utah-cs!esunix!bpendlet
-
-             Reality is stranger than most can imagine.

------------------------------

End of SPACE Digest V9 #301
*******************