🚀 go-pugleaf

Archive-name: space/diff

DIFFS SINCE LAST FAQ POSTING (IN POSTING ORDER)

(These are hand-edited context diffs; do not attempt to use them to patch
old copies of the FAQ).

===================================================================
diff -t -c -r1.12 FAQ.intro
*** /tmp/,RCSt1a05558	Sat Oct 31 17:40:55 1992
--- FAQ.intro	Sat Oct 31 17:38:13 1992
***************
*** 167,177 ****
	      Planetary mission references

      11  Upcoming planetary probes - missions and schedules
	      Galileo
	      Mars Observer
!	      CRAF
!	      Cassini
	      Other space science missions

      12  Controversial questions
	      What happened to the Saturn V plans
--- 167,180 ----
	      Planetary mission references

      11  Upcoming planetary probes - missions and schedules
+	      Cassini
	      Galileo
+	      Magellan
	      Mars Observer
!	      TOPEX/Poseidon
!	      Ulysses
	      Other space science missions
+	      Proposed missions

      12  Controversial questions
	      What happened to the Saturn V plans

===================================================================
diff -t -c -r1.12 FAQ.net
*** /tmp/,RCSt1a05563	Sat Oct 31 17:40:57 1992
--- FAQ.net	Sat Oct 31 17:38:19 1992
***************
*** 35,44 ****
      sites interested in receiving the news group to which the article was
      posted.

!     Gateway machines serve to redirect Usenet netnews into Internet and
!     BITNET mailing lists and vice versa. If you can receive netnews, its
!     more flexible interface usually makes it the preferred option to getting
!     on one of the main mailing lists.

  MAILING LISTS

--- 35,45 ----
      sites interested in receiving the news group to which the article was
      posted.

!     Gateway machines redirect the Usenet sci.space group into Internet and
!     BITNET mailing lists and vice versa; the other Usenet groups are not
!     accessible as mailing lists. If you can receive netnews, its more
!     flexible interface and access to a wider range of material usually make
!     it the preferred option.

  MAILING LISTS

***************
*** 47,53 ****
      in over a decade). Email space-request@isu.isunet.edu (message body
      should be in the format 'subscribe space John Public') to join. Note
      that the moderated SPACE Magazine list is defunct at present for lack of
!     a moderator.

      Elements is a moderated list for fast distribution of Space Shuttle
      Keplerian Elements before and during Shuttle flights. NASA two line
--- 48,57 ----
      in over a decade). Email space-request@isu.isunet.edu (message body
      should be in the format 'subscribe space John Public') to join. Note
      that the moderated SPACE Magazine list is defunct at present for lack of
!     a moderator. Old copies of SPACE Digest since its inception in 1981 are
!     available by anonymous FTP. Retrieve
!	  julius.cs.qub.ac.uk:pub/SpaceDigestArchive/README
!     for further details.

      Elements is a moderated list for fast distribution of Space Shuttle
      Keplerian Elements before and during Shuttle flights. NASA two line
***************
*** 114,123 ****
      ELECTRONIC JOURNAL OF THE ASA
	  Don Barry (don@chara.gsu.edu) posts the monthly Electronic Journal
	  of the Astronomical Society of the Atlantic to sci.astro.
-
-     ESA BULLETIN
-	  Harm Munk (munk@prl.philips.nl) posts summaries of articles in the
-	  quarterly _ESA Bulletin_ and the _ESA Journal_.

      FLIGHT INTERNATIONAL
	  Swaraj Jeyasingh (sjeyasin@axion.bt.co.uk) posts summaries of
--- 118,123 ----

===================================================================
diff -t -c -r1.12 FAQ.data
*** /tmp/,RCSt1a05568	Sat Oct 31 17:40:59 1992
--- FAQ.data	Sat Oct 31 17:38:09 1992
***************
*** 279,284 ****
--- 279,289 ----
      available by anonymous FTP from export.lcs.mit.edu (18.24.0.12) in
      contrib/xsat1.0.tar.Z. Contact Dave Curry (davy@ecn.purdue.edu)
      for more information.
+
+     Xsky, a computerized sky atlas for the X Window System, is available for
+     anonymous FTP on arizona.edu in the directory [.SOFTWARE.UNIX.XSKY] as
+     xsky.tarz. Contact Terry R. Friedrichsen (terry@venus.sunquest.com) for
+     more information.

      The "Variable Stars Analysis Software Archive" is available via
      anonymous FTP from kauri.vuw.ac.nz (130.195.11.3) in directory

===================================================================
diff -t -c -r1.12 FAQ.constants
*** /tmp/,RCSt1a05583	Sat Oct 31 17:41:05 1992
--- FAQ.constants	Sat Oct 31 17:38:05 1992
***************
*** 48,94 ****

	      a = 4 pi**2 r / t^2

!	  For circular Keplerian orbits, where u is gravitational constant, a is
!	      semimajor axis of orbit, P is period.
!	      v^2 = u/a
!	      P   = 2pi/(Sqrt(u/a^3))
!	      u   = G * M (can be measured much more accurately than G or M)
!
!	      Vc = sqrt(M * G / r)
!	      Vesc = sqrt(2 * M * G / r) = sqrt(2) * Vc
!	      The period of an eccentric orbit is the same as the period of a
!		 circular orbit with the same semi-major axis
!	      1/2 V**2 - G * M / r = K	(conservation of energy)
!		      where
!	      Vc   = velocity of a circular orbit (you have something like this)
	      Vesc = escape velocity
	      K    = -G * M / 2 / a
-	      M    = Mass of orbited object
-	      G    = Gravitational constant
	      r    = radius of orbit (measured from center of mass of system)
	      V    = orbital velocity

	  Change in velocity required for a plane change of angle phi in a
	  circular orbit:

	      delta V = 2 sqrt(GM/r) sin (phi/2)

!	  Energy to put mass m into a circular orbit (ignoring rotational
!	  velocity of the Earth, which reduces the energy a bit).

	      GMm (1/Re - 1/2Rcirc)
	      Re = radius of the earth
	      Rcirc = radius of the circular orbit.

!	  Classical rocket equation (dv = change in velocity, ve = exhaust
!	    velocity, x = reaction mass, m1 = rocket mass excluding reaction
!	    mass):
!
!	      dv = Ve * ln((m1 + x) / m1)
!		 = Ve * ln((final mass) / (initial mass))
!	      Ve = Isp * g = exhaust velocity, m / s
	      Isp = specific impulse of engine
!	      g = 9.80665 m / s^2

	  Relativistic rocket equation (constant acceleration)

--- 48,97 ----

	      a = 4 pi**2 r / t^2

!	  For circular Keplerian orbits where:
!	      Vc   = velocity of a circular orbit
	      Vesc = escape velocity
+	      M    = Total mass of orbiting and orbited bodies
+	      G    = Gravitational constant (defined below)
+	      u    = G * M (can be measured much more accurately than G or M)
	      K    = -G * M / 2 / a
	      r    = radius of orbit (measured from center of mass of system)
	      V    = orbital velocity
+	      P    = orbital period
+	      a    = semimajor axis of orbit

+	      Vc   = sqrt(M * G / r)
+	      Vesc = sqrt(2 * M * G / r) = sqrt(2) * Vc
+	      V^2  = u/a
+	      P    = 2 pi/(Sqrt(u/a^3))
+	      K    = 1/2 V**2 - G * M / r (conservation of energy)
+
+	      The period of an eccentric orbit is the same as the period
+		 of a circular orbit with the same semi-major axis.
+
	  Change in velocity required for a plane change of angle phi in a
	  circular orbit:

	      delta V = 2 sqrt(GM/r) sin (phi/2)

!	  Energy to put mass m into a circular orbit (ignores rotational
!	  velocity, which reduces the energy a bit).

	      GMm (1/Re - 1/2Rcirc)
	      Re = radius of the earth
	      Rcirc = radius of the circular orbit.

!	  Classical rocket equation, where
!	      dv  = change in velocity
	      Isp = specific impulse of engine
!	      Ve  = exhaust velocity
!	      x   = reaction mass
!	      m1  = rocket mass excluding reaction mass
!	      g   = 9.80665 m / s^2
!
!	      Ve  = Isp * g
!	      dv  = Ve * ln((m1 + x) / m1)
!		  = Ve * ln((final mass) / (initial mass))

	  Relativistic rocket equation (constant acceleration)


===================================================================
diff -t -c -r1.12 FAQ.probe
*** /tmp/,RCSt1a05603	Sat Oct 31 17:41:12 1992
--- FAQ.probe	Sat Oct 31 17:38:22 1992
***************
*** 102,112 ****
      to do so.

      PIONEER Venus 1 (1978) (also known as PIONEER Venus Orbiter, or PIONEER
!     12) is still orbiting Venus and returning data to Earth. It is expected
!     to enter the Venusian atmosphere and burn up in 1992. PVO made the first
!     radar studies of the planet's surface via probe. PIONEER Venus 2 (also
!     known as PIONEER 13) sent four small probes into the atmosphere in
!     December of 1978. The main spacecraft bus burned up high in the
      atmosphere, while the four probes descended by parachute towards the
      surface. Though none were expected to survive to the surface, the Day
      probe did make it and transmitted for 67.5 minutes on the ground before
--- 102,111 ----
      to do so.

      PIONEER Venus 1 (1978) (also known as PIONEER Venus Orbiter, or PIONEER
!     12) burned up in the Venusian atmosphere on October 8, 1992. PVO made
!     the first radar studies of the planet's surface via probe. PIONEER Venus
!     2 (also known as PIONEER 13) sent four small probes into the atmosphere
!     in December of 1978. The main spacecraft bus burned up high in the
      atmosphere, while the four probes descended by parachute towards the
      surface. Though none were expected to survive to the surface, the Day
      probe did make it and transmitted for 67.5 minutes on the ground before

===================================================================
diff -t -c -r1.12 FAQ.new_probes
*** /tmp/,RCSt1a05608	Sat Oct 31 17:41:14 1992
--- FAQ.new_probes	Sat Oct 31 17:38:20 1992
***************
*** 44,56 ****


      MAGELLAN - Venus radar mapping mission. Has mapped almost the entire
!     surface at high resolution. Funding for continuing operations into
!     mapping cycle 4 and beyond has been cut from the proposed NASA budget.


      MARS OBSERVER - Mars orbiter including 1.5 m/pixel resolution camera.
!     Launch scheduled 9/16/1992 aboard Titan III; arrival in 8/93, operations
!     start 11/93 for one martian year (687 days).


      TOPEX/Poseidon - Joint US/French Earth observing satellite, launched in
--- 93,105 ----


      MAGELLAN - Venus radar mapping mission. Has mapped almost the entire
!     surface at high resolution. Currently (11/92) in mapping cycle 4,
!     collecting a global gravity map.


      MARS OBSERVER - Mars orbiter including 1.5 m/pixel resolution camera.
!     Currently (11/92) in transit to Mars arrival in 8/93. Operations start
!     11/93 for one martian year (687 days).


      TOPEX/Poseidon - Joint US/French Earth observing satellite, launched in
--- 110,140 ----
      will increase understanding of how heat is transported in the ocean.


!     ULYSSES- European Space Agency probe to study the Sun from an orbit over
!     its poles. Launched in late 1990, it carries particles-and-fields
!     experiments (such as magnetometer, ion and electron collectors for
!     various energy ranges, plasma wave radio receivers, etc.) but no camera.

!     Since no human-built rocket is hefty enough to send Ulysses far out of
!     the ecliptic plane, it went to Jupiter instead, and stole energy from
!     that planet by sliding over Jupiter's north pole in a gravity-assist
!     manuver in February 1992. This bent its path into a solar orbit tilted
!     about 85 degrees to the ecliptic. It will pass over the Sun's south pole
!     in the summer of 1993. Its aphelion is 5.2 AU, and, surprisingly, its
!     perihelion is about 1.5 AU-- that's right, a solar-studies spacecraft
!     that's always further from the Sun than the Earth is!

!     While in Jupiter's neigborhood, Ulysses studied the magnetic and
!     radiation environment. For a short summary of these results, see
!     *Science*, V. 257, p. 1487-1489 (11 September 1992). For gory technical
!     detail, see the many articles in the same issue.


      OTHER SPACE SCIENCE MISSIONS (note: this is based on a posting by Ron
      Baalke in 11/89, with ISAS/NASDA information contributed by Yoshiro
      Yamada (yamada@yscvax.ysc.go.jp). I'm attempting to track changes based
      on updated shuttle manifests; corrections and updates are welcome.

      1993 Missions
	  o Wind [Aug, Delta II rocket]
	      Satellite to measure solar wind input to magnetosphere.