Control rooms and antennas: how NASA keeps in touch with its spacecraft

Drawn from 11 sources: NASA (6), NASA Space Communications and Navigation (SCaN), NASA Science, NASA Office of Inspector General and 2 others. About 7 minutes. Checked October 1, 2026.

A spacecraft is only half of a mission. The other half is on the ground: a control room where people decide what the spacecraft will do next, and a chain of antennas that carries their commands up and the spacecraft’s data down. Some pieces of that system are older than NASA itself. Today NASA’s Space Communications and Navigation program runs two networks that hand missions off to each other: the Near Space Network, with ground stations and relay satellites for spacecraft in Earth and lunar orbit, and the Deep Space Network, with antenna complexes in California, Spain and Australia for everything farther out. Together they support more than 100 missions.¹

Eighteen stations to follow one astronaut

Before NASA existed, the Naval Research Laboratory’s Minitrack network—ten ground stations from Santiago, Chile, to Grand Turk—was already following satellites. It tracked Sputnik in 1957, though its stations could “see” the satellite for only part of each orbit and data moved at 30 bits per second, about the speed of a teletype. When Explorer 1 launched in January 1958, JPL received its signals at portable stations in Nigeria, Singapore and California. NASA absorbed Minitrack when it opened, and with it the principles that guided its communications for decades: ground stations spread around the globe for coverage, redundancy for reliability, and international partners for worldwide reach.¹

Human spaceflight demanded far more. For Project Mercury, eighteen ground stations were chosen for the communications network; eleven of them doubled as precision radar tracking sites, two were ships at sea and seven were built in foreign countries. The network spanned three oceans and three continents through about 177,000 miles of communications circuits, and in November 1959 its cost was estimated at $41 million. By the end of the program the tracking network accounted for a third of Mercury’s $384 million cost.² The Mercury Space Flight Network was completed in July 1961, in time to keep contact with astronauts orbiting at 17,500 miles per hour.¹

Mercury Control directed the flights from Florida

Mercury Control during the first orbit of John Glenn’s Friendship 7, February 20, 1962. The wall map traces his three orbits over the tracking stations.

NASA

Houston takes over mission control in 1965

On September 19, 1961, NASA announced that a new Manned Spacecraft Center would be built near Houston. It would develop crewed spacecraft and hold operational control of all crewed missions.⁴ The Cape control room was enlarged for Gemini to ten flight-controller consoles, but the new Mission Control Center in Houston took over with Gemini 4 in June 1965. More than a thousand reporters came to Houston for that flight, drawn partly by the knowledge that the new control center would operate for the first time.^3,11

On July 20, 1969, three stations received the first steps on the Moon at once. When Goldstone’s television feed had equipment problems and the Moon rose higher in the Australian sky, Houston switched to video from Honeysuckle Creek near Canberra and then from the Parkes radio telescope in New South Wales, combining it with Goldstone’s audio. After the explosion on Apollo 13 in April 1970, engineers at Parkes reconfigured their equipment in roughly 12 hours instead of the usual week to help track the crew home.¹

Relay satellites replaced most of the ground stations

A ground station can talk to an Earth-orbiting spacecraft only while it passes overhead, so early crews and satellites spent most of each orbit out of contact. Relay satellites in high orbit changed that.¹

From ground stations to relay satellites

1. 1975

   ATS-6 relays Apollo–Soyuz¹

   A single relay satellite raises coverage from 15 percent to over 50 percent.

2. 1983

   TDRS-1 rescued¹

   After its upper stage failed, engineers used tiny thrusters to nudge it 8,600 miles higher to geostationary orbit. It served for 26 years.

3. 1989

   Three TDRS satellites in place¹

   Near-Earth coverage reaches 85 percent, against the ground network’s 15.

4. 1998

   Guam ground terminal¹

   Closes the gap over the Indian Ocean; coverage passes 99 percent.

5. 2024

   TDRS stops taking new missions¹

   The transition to commercial communications providers begins.

6. 2025

   Commercial Near Space Network¹

   Four companies receive contracts worth up to $4.82 billion to provide services through 2034.

The Deep Space Network: three sites spaced around the world

Beyond Earth orbit, NASA relies on the Deep Space Network, the largest and most sensitive scientific telecommunications system in the world. It has three complexes placed about 120 degrees apart: at Goldstone in California’s Mojave Desert, at Robledo near Madrid, and at Tidbinbilla near Canberra. The spacing lets the network keep a spacecraft in view constantly as Earth rotates: before a distant spacecraft sinks below the horizon at one site, another can pick up the signal and carry on communicating.^5,6 The network was established in 1963, when the stations were linked to JPL’s new Space Flight Operations Facility. JPL manages it under NASA’s contract with Caltech, and NASA’s agreements with the Australian and Spanish governments cover day-to-day operations at the foreign sites.^1,7

A deep-space network booked beyond its capacity

DSS-53 at Madrid, the fourth of six new 34-meter antennas, went online in February 2022.

NASA/JPL-Caltech

In July 2023, NASA’s Inspector General found the Deep Space Network operating at capacity and oversubscribed: missions requested more antenna time than the network could provide, with demand exceeding supply at times by as much as 40 percent. The network was supporting nearly 60 NASA and partner missions, and NASA’s own studies projected excess demand of about 50 percent by the 2030s. In the previous five years, missions had received between 8,500 and 15,000 fewer tracking hours than they requested.⁷

40%

how far demand for Deep Space Network time has exceeded supply at peak times⁷

$706M

cost of the antenna upgrade project, up 68 percent from $419 million⁷

2029

when the last of six new 34-meter antennas is due, in Canberra⁸

The strain will grow when the largest users—the Perseverance rover, the James Webb Space Telescope and the Artemis missions—sit in the same part of the sky competing for the same antennas. Missions negotiate antenna time among themselves; in 2023, unlike the Near Space Network, the Deep Space Network had no priority list. NASA’s answer, begun more than 15 years ago, was the Deep Space Network Aperture Enhancement Project, which is adding six new 34-meter antennas. Changes to its scope raised its expected cost from $419 million to $706 million, and NASA did not expect the three sites to have fully functional antennas until at least 2029, nearly five years late.^7,8

Artemis II: two networks, one control room, a planned 41-minute silence

The Artemis missions use both networks. For Artemis II, the Mission Control Center at Johnson Space Center in Houston tracked the rocket, its upper stage and Orion through coordinated handoffs between assets on Earth and in space. The Near Space Network, managed by Goddard, covered launch and the hours in Earth orbit; after the burn that sent Orion toward the Moon, primary support moved to the Deep Space Network.⁹

The flight, from April 1 to 10, 2026, took the four astronauts 252,756 miles from Earth at their farthest point.¹⁰ NASA planned a communications blackout of about 41 minutes as Orion passed behind the Moon, cutting off radio signals to and from Earth; similar blackouts occurred during Apollo. Orion also carried a laser communications terminal to send crew and science data over laser links, and data from the spacecraft was compressed after reaching Earth to give priority to crew communications and mission data.⁹

Those blackouts remain part of every mission on or around the far side of the Moon, as long as the antennas are all on Earth. NASA’s Lunar Communications Relay and Navigation Systems project is working with industry to place relay satellites around the Moon, which would do for lunar missions what the relay satellites of the 1980s did for spacecraft in Earth orbit.⁹