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(meteorobs) Excerpts from "CCNet 26/2001 - 14 Feb 2001: NEAR-SHOEMAKER SPECIAL IV"
------- Forwarded Message
From: Peiser Benny <B.J.Peiser@livjm.acdot uk>
To: cambridge-conference <cambridge-conference@livjm.acdot uk>
Subject: CCNet, 14 February 2001: NEAR-SHOEMAKER SPECIAL IV
Date: Wed, 14 Feb 2001 10:39:01 -0000
CCNet 26/2001 - 14 February 2001: NEAR-SHOEMAKER SPECIAL IV
-----------------------------------------------------------
(1) NEAR SHOEMAKER UPDATE
Ron Baalke <baalke@jpl.nasadot gov>
(2) NEAR SHOEMAKER MISSION COULD BE EXTENDED
Space.com, 13 February 2001
(3) JPL NAVIGATORS GUIDE NEAR TO HISTORIC LANDING ON ASTEROID EROS
Ron Baalke <baalke@zagami.jpl.nasadot gov>
(4) ENCORE FLIGHT MULLED FOR AMAZING ASTEROID LANDER
CNN, 13 February 2001
(5) RELAUNCH OPTIONS?
Benny Peiser <B.J.Peiser@livjm.acdot uk>
(6) SPACECRAFT MAY GET EXTRA WEEK ON ASTEROID
CNN, 13 February 2001
[...]
(11) THANK-YOU NOTE AT RENDEZVOUS WITH EROS
David H. Levy <david@jarnac.org>
[...]
(13) PLANS FOR NEAR?
Michael Paine <mpaine@tpgi.com.au>
[...]
============
(1) NEAR SHOEMAKER UPDATE
>From Ron Baalke <baalke@jpl.nasadot gov>
http://near.jhuapldot edu/
NEAR Shoemaker Update
February 13, 2001
The NEAR mission operations team disabled a redundant engine firing today
that would have been activated if it became necessary to adjust the
spacecraft's orientation in order to receive telemetry from the ground. But
because NEAR Shoemaker landed with a favorable orientation, and telemetry
has already been received, it is no longer necessary to move the spacecraft
from its resting-place on the surface of Eros.
==================
(2) NEAR SHOEMAKER MISSION COULD BE EXTENDED
>From Space.com, 13 February 2001
http://www.space.com/scienceastronomy/solarsystem/near_extension_010213.html
By Leonard David
Senior Space Writer
posted: 04:00 pm ET
13 February 2001
NASA is studying an option to continue operating the NEAR Shoemaker probe on
Asteroid 433 Eros for an extended period, beyond the February 14 cutoff date
that had been planned earlier.
"An option is to continue running on the surface from seven to 10 days,"
said Don Savage, a NASA spokesperson.
An announcement on whether the mission will be extended is set for 1:00 p.m.
EST (18:00 GMT) Wednesday at the Applied Physics Laboratory, which operates
the mission for NASA. Engineers and scientists there also will announce a
decision on whether to re-launch the spacecraft for a brief photo cruise
across the asteroid's surface.
SPACE.com will offer full coverage of the news conference, including
streaming video, starting at 1:00 p.m. EST.
Scientists are delighted with the high-quality, close-up images of Asteroid
433 Eros that NEAR Shoemaker spacecraft transmitted as it floated to a
historic landing on the rocky surface nearly 200 million miles (322 million
kilometers) from Earth on Monday, February 12.
NEAR Shoemaker was not equipped with landing gear for the first-ever,
odds-against spacecraft rendezvous with an asteroid. The daring dive was
called for as the spacecraft's mission drew toward an anticipated close,
with the mission out of money, the spacecraft out of fuel and NASA initially
denying more "listening time" on its network of deep-space radio antennas.
Now there is talk of gathering more data and extending the mission, with the
operational probe already sitting on the surface of an asteroid.
Possibly to be kept in operation at a low data rate is the X-ray/Gamma Ray
Spectrometer (XGRS) that is onboard the parked spacecraft, Savage said.
Monies to operate the spacecraft for the longer period would come out of
reserves built into the mission, Savage said.
Re-launch decision unclear
Re-launch of the spacecraft from Eros, allowing it to fire its thrusters a
final time to skim across the asteroid's surface and take more close-up
images, was still under discussion through Tuesday.
"A number of options are out there and we expect to hear and review all of
them soon," Savage told SPACE.com.
Telemetry has been received from the probe. All indications are that onboard
equipment is functioning well. The craft's solar panels are soaking up
plenty of power.
A command that was input into the spacecraft prior to touchdown -- a
sequence that would have fired off the probe's engines on Wednesday -- was
disabled shortly after landing, said Michael Buckley, a spokesman for APL.
"Right now, we're trying to assess how healthy the spacecraft is and what
can be done to obtain more telemetry, and more information from NEAR
Shoemaker," Buckley told SPACE.com.
According to sources close to the project, the option to blast off from Eros
is being heavily discussed. New data on remaining fuel onboard the craft is
being assessed. Early indications are, however, that little fuel remains to
attempt the liftoff.
If enough fuel were available, due to the asteroid's weak gravity field,
NEAR Shoemaker could hop high over Eros while snapping yet more images,
according to SPACE.com sources.
NEAR team spokeswoman Helen Worth told one online space site that it was
"highly unlikely" the re-launch attempt will be made.
A similar type maneuver was done in the 1960's with the robotic Surveyor
moon lander.
On November 17, 1967, ground controllers fired Surveyor 6's engines for 2.5
seconds. The craft lifted off the lunar surface and moved a short distance
from the original landing site within the Moon's Sinus Medii region. The
craft moved all of 8 feet (2.4 meters) from its first touchdown spot.
Other final decisions on what can be done with a still-working NEAR
Shoemaker are to be detailed at the news conference tomorrow.
Copyright 2001, Space.com
===============
(3) JPL NAVIGATORS GUIDE NEAR TO HISTORIC LANDING ON ASTEROID EROS
>From Ron Baalke <baalke@zagami.jpl.nasadot gov>
MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 TELEPHONE (818) 354-5011
http://www.jpl.nasadot gov
Contacts: JPL/ Martha Heil (818) 354-0850
Applied Physics Lab/Helen Worth (240) 228-5113
Mike Buckley (240) 228-7536
FOR IMMEDIATE RELEASE February 13, 2001
JPL NAVIGATORS GUIDE NEAR TO HISTORIC LANDING ON ASTEROID EROS
With fingers flying across calculator keypads as new guidance data flowed
in, JPL space navigators yesterday used fast math, and lots of it, to help
carefully nudge NASA's NEAR Shoemaker spacecraft to its historic touchdown
on the surface of asteroid Eros.
The success of the landing, and the spacecraft's continuing communications
with controllers via NASA's JPL- managed Deep Space Network, astounded even
the most optimistic of scientists and engineers associated with the mission.
"Unbelievable," was how deputy navigation team chief Jim Miller of JPL
described the landing and the fact that the spacecraft is still alive and
communicating with Earth.
NEAR Shoemaker project managers at Johns Hopkins University's Applied
Physics Lab (APL) in Laurel, Md., reported today that the team is assessing
the overall health and performance of the spacecraft and evaluating ways to
gather additional information from the craft. A decision on how to do that
could be reached as early as today, mission managers said.
Eros is about the size of Manhattan Island. NEAR Shoemaker landed on a
rock-strewn plain of the asteroid at 12:02:10 Pacific Standard Time (3:02:10
EST) on Monday, Feb. 12. It had slowed to a gentle 1.9 meters per second (4
miles per hour) just before finally coming to rest after a journey of 3.2
billion kilometers (2 billion miles).
Cheers and congratulations filled the NEAR Shoemaker mission operations
center at Maryland's APL yesterday as images and engineering data arrived
from the spacecraft. APL built the spacecraft and manages the mission for
NASA.
The NEAR Shoemaker navigation team at JPL is headed by Bobby Williams and
includes Miller, Bill Owen, Mike Wang, Cliff Helfrich, Peter Antreasian and
Steve Chesley. JPL's Dr. Donald Yeomans serves as the mission's radio
science principal investigator, and JPLers Jon Gorgini and Alex Konopliv are
team members.
The last image from NEAR Shoemaker was snapped a mere 120 meters (394 feet)
from the asteroid's surface and covers an area 6 meters (20 feet) wide. As
NEAR Shoemaker touched down, it began sending a beacon, assuring the team
that the small spacecraft had landed gently. The signal was
identified by radar science data, and about an hour later was locked onto by
NASA's Deep Space Network antennas, which will monitor the spacecraft until
Feb. 14.
NEAR Shoemaker's final descent started with an engine firing at 7:31 a.m.
PST (10:31 a.m. EST), which nudged the spacecraft toward Eros from about 16
miles (26 kilometers) away. Then four braking maneuvers brought the
spacecraft to rest on the asteroid's surface in an area just outside a
saddle-shaped depression, Himeros. When it touched down, NEAR Shoemaker
became the first spacecraft ever to land, or even attempt to land, on an
asteroid. The success was sweetened by the fact that it was not designed as
a lander.
The spacecraft spent the last year in a close-orbit study of asteroid 433
Eros, a near-Earth asteroid that is currently 316 million kilometers (196
million miles) from Earth. During that time it collected 10 times more data
than originally planned and completed all its science goals before
attempting its descent to the asteroid.
For mission updates, images and other information, see
http://near.jhuapldot edu .
JPL, a NASA center, is a division of the California Institute of Technology
in Pasadena.
=========
(4) ENCORE FLIGHT MULLED FOR AMAZING ASTEROID LANDER
>From CNN, 13 February 2001
http://www.cnn.com/2001/TECH/space/02/13/near.landing.01/index.html
February 13, 2001
Web posted at: 1:02 p.m. EST (1802 GMT)
By Miles O'Brien
CNN Space Correspondent
LAUREL, Maryland (CNN) - What next for NEAR-Shoemaker? On the morning after
the NASA robot ship made the first landing on an asteroid, mission
scientists were trying to figure out how much more science they could
squeeze from the small craft.
One of several options being debated: firing up the thrusters for a short
encore flight. But NEAR (Near Earth Asteroid Rendezvous) managers said that
would happen no earlier than Wednesday.
Instead, they planned to spend Tuesday looking at the data stream sent from
their half-ton spacecraft, some 196 million miles (315 million km) away.
The information so far indicates NEAR-Shoemaker is alive, well and
generating plenty of power from its solar panels. It is an astounding
outcome no one predicted. The vessel was not designed to land.
The team is taking its time deciding on a possible liftoff from the asteroid
Eros, an oddly shaped space rock 21 miles (34 km) in length.
Once they fire the rocket thrusters, there is a strong likelihood they will
not hear from the probe again. A second landing might very well damage the
craft or knock its antenna or solar arrays out of alignment.
There is little time for debate. NASA will cut off NEAR- Shoemaker's access
to the tracking system known as the Deep Space Network at on Wednesday at 7
p.m. EST, ending the five-year NEAR mission.
The NEAR team, located at the Johns Hopkins Applied Physics Laboratory in
Laurel, Maryland, conducted the asteroid landing to gain "bonus science"
after an already successful mission.
During its yearlong orbit of Eros, NEAR-Shoemaker beamed a colossal amount
of information about the asteroid, including 160,000 images of its surface.
It was 10 times more data than scientists anticipated.
The automobile-sized craft sent back about 100 images during its descent on
Monday, offering the closest look yet at an asteroid. The images are able to
resolve objects as small as a centimeter.
Copyright 2001, CNN
==============
(5) RELAUNCH OPTIONS?
>From Benny Peiser <B.J.Peiser@livjm.acdot uk>
Sent: Tuesday, February 13, 2001 8:12 AM
To: Andrew Cheng <Andy.Cheng@jhuapldot edu>
Subject: RELAUNCH OF NEAR SHOEMAKER TOMORROW?
Dear Andrew,
Can you confirm the story reported on Space.com about considerations by the
mission team to relaunch NEAR tomorrow?
Regards, Benny
- ----------
>From Andrew Cheng <Andy.Cheng@jhuapldot edu>
To: Benny Peiser <B.J.Peiser@livjm.acdot uk>
Sent: 13 February 2001 15:18
Subject: RELAUNCH OF NEAR SHOEMAKER TOMORROW?
We are discussing that now amongst ourselves - the spacecraft is apparently
fine, but we are also considering a request from our science team to make
some measurements on the surface.
Andy
=============
(6) SPACECRAFT MAY GET EXTRA WEEK ON ASTEROID
>From CNN, 13 February 2001
http://www.cnn.com/2001/TECH/space/02/13/near.landing.02/index.html
February 13, 2001
Web posted at: 7:26 p.m. EST (0026 GMT)
By Miles O'Brien
CNN Space Correspondent
LAUREL, Maryland (CNN) -- The NEAR-Shoemaker spacecraft may remain on the
surface of the Eros asteroid longer than originally planned.
NASA is expected to announce Wednesday that the NEAR (Near Earth Asteroid
Rendezvous) mission will be extended another week to allow time for the
robot ship to collect more readings about the constituent properties of the
asteroid, sources told CNN on Tuesday.
Because NEAR is on the surface of Eros, scientists believe it will take
remarkably accurate readings using a gamma ray. That data will be sent back
to Earth using NASA's Deep Space Network.
Officials are also expected to announce at the Wednesday news conference --
scheduled for 1 p.m. EST -- that NEAR could take another short flight after
the weeklong observation stint.
Mission managers spent Tuesday in the control center at the Johns Hopkins
University Applied Physics Laboratory looking at the data stream from their
1,100-pound spacecraft 196 million miles away.
The information scientists have seen so far indicates NEAR-Shoemaker is
generating plenty of power from its solar arrays. Such a feat has surprised
scientists -- the vessel was not designed to land.
The team is taking its time deciding on a possible liftoff. Once they fire
the rocket thrusters, there is a strong likelihood they will not hear from
the probe again. A second landing might very well damage the craft or knock
its antenna or solar arrays out of alignment.
The asteroid landing idea was an afterthought to an already successful
mission. NEAR-Shoemaker spent a year orbiting the asteroid EROS, beaming
back 160,000 images. It was 10 times more data than scientists anticipated.
The hundred images sent back during the descent offer the closest look yet
at an asteroid. The images are able to resolve objects as small as a
centimeter.
Copyright 2001, CNN
============================
* LETTERS TO THE MODERATOR *
============================
(11) THANK-YOU NOTE AT RENDEZVOUS WITH EROS
>From David H. Levy <david@jarnac.org>
Dear Benny,
In a few hours, Carolyn Shoemaker will be arriving here from her Maryland
visit, where she watched the incoming images and shared the excitement of
the NEAR-Shoemaker demise. Tonight she will join Wendee and me here as we
continue our own comet search program.
The confluence of events that resulted in NEAR-Shoemaker's landing on Eros
is amazing. In its infancy the Earth was bombarded by visitors from space,
asteroids and comets that brought their supply of organic particles that led
eventually to life on Earth. Yesterday, that life returned the favor.
NEAR-Shoemaker's landing on Eros was a thank-you note to those ancient
asteroids and comets, and what they left us.
David H. Levy
=============
(13) PLANS FOR NEAR?
>From Michael Paine <mpaine@tpgi.com.au>
Dear Benny
The Space.com story that you posted indicating that NEAR might be relaunched
seems to have changed. I cannot find any reference to this idea.
[...]
P.S. A new NEAR relaunch story is at:
http://www.space.com/scienceastronomy/solarsystem/near_extension_010213.html
MODERATOR'S NOTE: The original relaunch story by Leonard David (as posted
yesterday on CCNet) couldn't be retrieved on the Space.com website because
the first paragraphs of his story were erased, for unknown reasons, shortly
after the news broke.
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