Question: Who is the astronaut that inspired the nickname of "Spacetown" for Derry, New Hampshire?

Context articles: New Hampshire Route 121
East Derry, New Hampshire
Taylor Mill State Historic Site
Derry, New Hampshire
New Hampshire Straw Poll
Pinkerton Academy
Derry (CDP), New Hampshire
Parkland Medical Center
Adams Memorial Building
Alan Shepard

New Hampshire Route 121 (abbreviated NH 121) is a 22.555 mi north–south state highway in Rockingham and Hillsborough counties in southeastern New Hampshire.
 The road winds through the communities of Atkinson, Hampstead, Sandown, Derry, Chester, and Auburn.
 The southern terminus of NH 121 is at the Massachusetts state line in Plaistow, where the road, named Atkinson Depot Road, continues into the city of Haverhill as an unnumbered local road (North Main Street) leading to Route 125.
 The northern terminus is at a traffic circle, where NH 121 meets New Hampshire Route 28 Bypass (the Londonderry Turnpike) in eastern Manchester.
 At this point, the road is known as Manchester Road.
East Derry, also known as the Upper Village, is an unincorporated community in the town of Derry in Rockingham County, New Hampshire.
 The village center constitutes the East Derry Historic District, listed on the National Register of Historic Places.
 It is located on a hill close to the geographic center of the town of Derry along East Derry Road, approximately 2 mi east of the built-up town center of Derry.
 East Derry has a separate ZIP code (03041) from the rest of the town of Derry.
 Alan Shepard lived in the village as a boy.
 Station #4 of the Derry Fire Department is located in the village.
The Taylor Mill State Historic Site is a state park of New Hampshire located in 71-acre Ballard State Forest in Derry, Rockingham County, in the southeast part of the state.
 The site is created to protect the 1799 mill known as Taylor Up and Down Sawmill.
 The sawmill is in operation and is open for visitors on weekends during the summer.
 The site is located on Island Pond Road, east of the downtown of Derry.
Derry is a town in Rockingham County, New Hampshire, United States.
 The population was 33,109 at the 2010 census.
 Although it is a town and not a city, Derry is the fourth most-populous community in the state.
 The town's nickname, "Spacetown", derives from the fact that Derry is the birthplace of Alan Shepard, the first astronaut from the United States in space.
 Derry was also for a time the home of the poet Robert Frost and his family.
The New Hampshire Straw Poll is a straw poll for the United States Republican presidential primary elections that was started in 2011 through promotion by ABC News and WMUR-TV.
 The first poll was held on Saturday, January 22, 2011, in Derry, New Hampshire, a year in advance of the New Hampshire primary, which as is traditional will be the first primary in the 2012 Republican Party presidential nomination process.
 Voters in the poll were among some 400 members of the state Republican Party attending a meeting at the Pinkerton Academy in Derry.
 As with all straw polls, the results are in no way binding.
Pinkerton Academy is a secondary school in Derry, New Hampshire, United States.
 It serves roughly 3,100 students, making it by far the largest high school in New Hampshire, more than 800 students greater than the next largest high school.
 Pinkerton's situation is unusual, as it is a private school which also serves as the "public" high school (grades 9–12) for the communities of Derry, Hampstead, Chester, Auburn, Candia, and Hooksett.
 Through arrangements with the towns, each town pays the tuition for their students to attend Pinkerton.
 For the 2014–15 school year, Hooksett students may attend Pinkerton, following the approval of a short-term enrollment agreement by the Hooksett School Board.
 Pinkerton Academy is a private, non-profit corporation administered by a headmaster, who in turn acts under the direction of a self-perpetuating board of trustees.
Derry is a census-designated place (CDP) in the town of Derry in Rockingham County, New Hampshire, United States.
 The CDP comprises the urban center of the town, as well as the village of East Derry and connected suburban areas.
 The population of the CDP was 22,015 at the 2010 census, out of 33,109 people in the entire town of Derry.
Parkland Medical Center is a hospital in Derry, New Hampshire with an urgent care center in Salem, New Hampshire.
 It is part of the Hospital Corporation of America (HCA).
 It currently is licensed for 86 beds and is a Trauma III hospital.
 Parkland started in 1983 in southern New Hampshire.
The Adams Memorial Building, now also known as the Derry Opera House, is a historic municipal building at 29 West Broadway near the center of Derry, New Hampshire.
 Built in 1904, it is a remarkably sophisticated Colonial Revival structure for what was at the time a small community.
 The building originally housed a variety of municipal offices and the local library.
 Local events are occasionally held in the theater ("opera house") of the building, located on the upper level.
 It was listed on the National Register of Historic Places in 1982.
 The theater is now operated by a local nonprofit arts organization.
Rear Admiral Alan Bartlett Shepard Jr. (November 18, 1923 – July 21, 1998) was an American astronaut, naval aviator, test pilot, and businessman.