Featured Research

from universities, journals, and other organizations

Earth Swingby Puts NEAR Spacecraft On Final Approach To Eros

Date:
January 22, 1998
Source:
National Aeronautics And Space Administration
Summary:
NASA's Near Earth Asteroid Rendezvous (NEAR) spacecraft, built by The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, MD, will become the first interplanetary spacecraft that can possibly be seen with the naked eye when it swings by Earth Jan. 22-23. The spacecraft's solar panels will reflect the Sun's rays onto the Earth in a greeting as it flies by for an adjustment of its trajectory to correctly align the spacecraft for a rendezvous with asteroid 433 Eros, its mission target.

NASA's Near Earth Asteroid Rendezvous (NEAR) spacecraft, built by The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, MD, will become the first interplanetary spacecraft that can possibly be seen with the naked eye when it swings by Earth Jan. 22-23. The spacecraft's solar panels will reflect the Sun's rays onto the Earth in a greeting as it flies by for an adjustment of its trajectory to correctly align the spacecraft for a rendezvous with asteroid 433 Eros, its mission target.

Launched Feb. 17, 1996, NEAR completed a flyby of the asteroid Mathilde in June 1997 and is now on its way back to Earth. Late Thursday, Jan. 22, the spacecraft will approach Earth over the Pacific Ocean traveling at about 20,000 mph. Because the United States will be in darkness as NEAR approaches, if there is no cloud cover, several geographic areas will be able to see the Sun reflecting off the spacecraft's solar panels, which will act as large mirrors. These sunglints will be visible on the East Coast, Friday, Jan. 23, at about 1:30 a.m. EST and the West Coast at about 1:45 a.m. EST (Thursday, 10:45 p.m. PST).

The spacecraft then swings around the Aleutian Islands and over Siberia before reaching its closest point to Earth, about 336 miles above Ahvaz in southwest Iran, Friday, Jan. 23, at 11:23 a.m. local time (2:23 a.m. EST), traveling at about 29,000 mph, its fastest speed for the swingby. Although NEAR will be close to Earth at this time, daylight may obscure its image.

The spacecraft then swings over Africa and on to Antarctica before pulling away from the Earth at a speed of about 15,000 mph. The swingby will have changed NEAR's trajectory to approximately 11 degrees south of the Earth's ecliptic plane, the orbital path the Earth takes as it circles the Sun, and put the spacecraft on target for its Jan. 10, 1999, rendezvous with Eros.

NEAR scientists and engineers are using the swingby as an opportunity to test performance and calibration of the spacecraft's six instruments and to practice coordinated multi-instrument observations of the type that will be used at Eros.

The Multispectral Imager, a visible light camera that will help determine the physical characteristics of Eros, and the NEAR-Infrared Spectrograph, used to study surface minerals, will be calibrated by comparing their readings of geological features with proven measurements of the same areas. These instruments will also be used to take images of the Earth along the spacecraft's path. NEAR's Magnetometer will be calibrated by comparing swingby data with known measurements of the Earth's magnetic field.

Other activities during the swingby will include using the X-Ray/Gamma-Ray Spectrometer to observe celestial gamma ray bursts and to collect data on gamma ray and X-ray backgrounds. These data are needed so scientists can better remove background impurities from the measurements to be made at Eros.

NEAR is expected to capture its first images of Eros, a 25-mile-long near-Earth asteroid, a few months prior to the 100th anniversary of the asteroid's discovery on Aug. 13, 1898. After reaching Eros, the spacecraft will start its orbit about 600 miles above the asteroid's surface, descending to 200 miles by February and coming as close as 10 miles during its yearlong study. Scientists will thoroughly map Eros and will examine its surface composition and physical properties. On Feb. 6, 2000, the mission is expected to end with a controlled descent onto the asteroid, sending dozens of high-resolution pictures as the spacecraft closes in on Eros.

The NEAR mission will be the first close-up study of an asteroid. APL, the first non-NASA center to conduct a NASA planetary mission, is managing the mission for NASA's Office of Space Science, Washington, DC.

Information on the NEAR mission, including a list of areas most likely to see NEAR's sunglint and how to find NEAR as it swings by Earth, is available on the Internet at:http://sd-www.jhuapl.edu/NEAR/.


Story Source:

The above story is based on materials provided by National Aeronautics And Space Administration. Note: Materials may be edited for content and length.


Cite This Page:

National Aeronautics And Space Administration. "Earth Swingby Puts NEAR Spacecraft On Final Approach To Eros." ScienceDaily. ScienceDaily, 22 January 1998. <www.sciencedaily.com/releases/1998/01/980122065247.htm>.
National Aeronautics And Space Administration. (1998, January 22). Earth Swingby Puts NEAR Spacecraft On Final Approach To Eros. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/1998/01/980122065247.htm
National Aeronautics And Space Administration. "Earth Swingby Puts NEAR Spacecraft On Final Approach To Eros." ScienceDaily. www.sciencedaily.com/releases/1998/01/980122065247.htm (accessed October 21, 2014).

Share This



More Space & Time News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Comet Siding Spring Grazes Mars' Atmosphere

Comet Siding Spring Grazes Mars' Atmosphere

Newsy (Oct. 19, 2014) A comet from the farthest reaches of the solar system passed extremely close to Mars this weekend, giving astronomers a rare opportunity to study it. Video provided by Newsy
Powered by NewsLook.com
Latin America Launches Communications Satellite

Latin America Launches Communications Satellite

AFP (Oct. 17, 2014) Argentina launches a home-built satellite, a first for Latin America. It will ride a French-made Ariane 5 rocket into orbit, and will provide cell phone, digital TV, Internet and data services to the lower half of South America. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
This Week @ NASA, October 17, 2014

This Week @ NASA, October 17, 2014

NASA (Oct. 17, 2014) Power spacewalk, MAVEN’s “First Light”, Hubble finds extremely distant galaxy and more... Video provided by NASA
Powered by NewsLook.com
Saturn's 'Death Star' Moon Might Have A Hidden Ocean

Saturn's 'Death Star' Moon Might Have A Hidden Ocean

Newsy (Oct. 17, 2014) The smallest of Saturn's main moons, Mimas, wobbles as it orbits. Research reveals it might be due to a global ocean underneath its icy surface. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins