diff --git a/gracedb/events/buildVOEvent.py b/gracedb/events/buildVOEvent.py
index f6dd0c7a9cacc9b0d68c554f7c62862409e27768..33511684e9d7bad6ec89b43d70730e429f46c812 100644
--- a/gracedb/events/buildVOEvent.py
+++ b/gracedb/events/buildVOEvent.py
@@ -7,7 +7,7 @@ buildVOEvent: Creates a complex VOEvent with tables
 See the VOEvent specification for details
 http://www.ivoa.net/Documents/latest/VOEvent.html
 """
-import math
+from scipy.constants import c, G, pi
 
 from VOEventLib.VOEvent import VOEvent, Who, Author, Param, How, What, Group
 from VOEventLib.VOEvent import Citations, EventIVORN
@@ -376,9 +376,6 @@ def buildVOEvent(event, serial_number, voevent_type, request=None, skymap_filena
                 max_hrss = max(hrss_values)
                 # From Min-A Cho: fluence = pi*(c**3)*(freq**2)*(hrss_max**2)*(10**3)/(4*G)
                 # Note that hrss here actually has units of s^(-1/2)
-                pi = math.pi
-                c = 2.99792E10
-                G = 6.674E-8
                 fluence = pi * pow(c,3) * pow(event.central_freq,2) 
                 fluence = fluence * pow(max_hrss,2)
                 fluence = fluence / (4.0*G)
@@ -404,9 +401,6 @@ def buildVOEvent(event, serial_number, voevent_type, request=None, skymap_filena
             # Note that hrss here actually has units of s^(-1/2)
             # XXX obviously need to refactor here.
             try:
-                pi = math.pi
-                c = 2.99792E10
-                G = 6.674E-8
                 fluence = pi * pow(c,3) * pow(event.frequency,2) 
                 fluence = fluence * pow(event.hrss,2)
                 fluence = fluence / (4.0*G)
diff --git a/gracedb/superevents/buildVOEvent.py b/gracedb/superevents/buildVOEvent.py
index 0e794c3be61a6013d88c2f110a8ff851f7339609..cd195fe42f6271600156b766d79889454ef4020f 100644
--- a/gracedb/superevents/buildVOEvent.py
+++ b/gracedb/superevents/buildVOEvent.py
@@ -7,7 +7,7 @@ buildVOEvent: Creates a complex VOEvent with tables
 See the VOEvent specification for details
 http://www.ivoa.net/Documents/latest/VOEvent.html
 """
-import math
+from scipy.constants import c, G, pi
 
 
 from VOEventLib.VOEvent import VOEvent, Who, Author, Param, How, What, Group
@@ -359,9 +359,6 @@ def construct_voevent_file(superevent, voevent, request=None,
                 max_hrss = max(hrss_values)
                 # From Min-A Cho: fluence = pi*(c**3)*(freq**2)*(hrss_max**2)*(10**3)/(4*G)
                 # Note that hrss here actually has units of s^(-1/2)
-                pi = math.pi
-                c = 2.99792E10
-                G = 6.674E-8
                 fluence = pi * pow(c,3) * pow(event.central_freq,2) 
                 fluence = fluence * pow(max_hrss,2)
                 fluence = fluence / (4.0*G)
@@ -388,9 +385,6 @@ def construct_voevent_file(superevent, voevent, request=None,
             # Note that hrss here actually has units of s^(-1/2)
             # XXX obviously need to refactor here.
             try:
-                pi = math.pi
-                c = 2.99792E10
-                G = 6.674E-8
                 fluence = pi * pow(c,3) * pow(event.frequency,2) 
                 fluence = fluence * pow(event.hrss,2)
                 fluence = fluence / (4.0*G)
diff --git a/requirements.txt b/requirements.txt
index fc1f3f7fb3f9afdbbe4057bfa8e941320be61531..4ff3f1021694b08a646c45d7584cded216535fc0 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -27,6 +27,7 @@ packaging==17.1
 phonenumbers==8.8.11
 python-ldap==3.1.0
 python-memcached==1.59
+scipy==1.2.1
 service_identity==17.0.0
 simplejson==3.15.0
 Sphinx==1.7.0